Walnut Trees

Walnut trees can be great shade trees and a delicious food source. Many people love the nuts they provide in the fall, making them an exciting addition to your garden or landscape. To thrive, walnut trees need specific soil conditions.

In general, walnut trees grow best in rich loamy soil that is well-drained but holds some moisture. These soils occur in river valleys, streams, and other bottomlands. Walnut trees have deep tap roots, so the soil should be at least three feet deep before encountering gravel or bedrock.

Knowing the best place to plant your new tree is essential to tree ownership. Continue reading to understand the best soil conditions for your walnut tree!

Types of Walnut Tree

In North America, two walnut trees are actively planted in landscapes; the Black Walnut and the English Walnut. The trees have very similar needs with a few differences worth noting. Each grows in slightly different climates.

Black Walnut grows best in USDA Hardiness zones 4-9, and English Walnut grows best in USDA Hardiness zones 3-7.

Black Walnut

According to the University of Minnesota Extension, the Black Walnut is also known as the Easter Black Walnut or American Walnut. This hardwood species is native to mixed deciduous forests in the eastern united states. 

Black Walnut trees occur north of Massachusetts, south to Florida, west to Minnesota, and Texas. This tree can occasionally occur in southern regions of Canada. 

The Black Walnut grows in USDA Hardiness zones 4-9. It is found alongside common trees such as sugar maple, silver maple, yellow poplar, oak, and beech. They will grow to 90-125 feet tall being one of the most giant trees in the North American forest!

Black Walnut Has Many Uses 

The wood of the Black Walnut tree is prized for its exceptional hardwood used in construction and carpentry; it is one of the most expensive woods on the market. 

Black Walnuts produce a round nut about two inches in diameter. They are single nuts enclosed by a hard outer green shell and fleshy husk that eventually turns black after the nut falls to the ground. When shelled, the nutmeat of the Black Walnut tree tastes richer and earthier than its English cousin.

Black Walnut trees are commercially available. We recommend planting a tree at least 12 inches tall and two to four years old! You can purchase one, like this Black Walnut Tree Sapling!

You can learn more about the differences between black walnut trees and other walnuts here if you’d like.

English Walnut

According to North Carolina Extension, English walnuts are not native to the United States but to Europe and Asia. This tree is cultivated for its sweet and white nut meat. It is smaller than the Black Walnut at only 40 to 60 feet tall. 

In the united states, cultivated English walnuts have escaped their farms and become naturalized in some forests. It has a similar range to the Black Walnut tree and can grow in USDA hardiness zones three through seven.

If you’re interested in growing your own English walnut tree, take a peak at our article on how much fruit walnut trees produce – it’s a doozy!

English Walnut Wood Uses 

It is grown for its wood, which is as hard as the Black Walnut tree, though lighter in color. Its nuts are sweeter than the Black Walnut, which is why this tree is most often cultivated for its nuts rather than its slightly more bitter cousin.

Despite the differences between these two trees, they have similar soil requirements and can be grown in similar locations, so for the purposes of this article, we will discuss their soil requirements together.

Best Soils For Walnut Trees

Both English and Black Walnut trees prefer moist, fertile soil to maintain a consistent growth rate.  Soil should drain well and be medium to fine textured. Good drainage is a must.

Now getting to the good stuff – soil comprises particles of various sizes. These particles are generally sorted into three categories; sand, silt, and clay. 

• Clay particles are the smallest and are prone to packing together tightly, creating poor drainage.
  
• Sand particles are the largest. Sandy soil drains quickly and does not hold water well, allowing air to reach plant roots easily.
  
• Silt particles lie in between and have some of the properties of both sand and clay.

The following soil types are ideal for walnut tree growth. Continue reading for more details on each.

• Loam.
• Sandy loam.
• Silt loam.
• Clay loam.

Loam

A loamy soil combines all three types of soil particles in equal amounts. This type of soil holds plenty of moisture while also draining well so air can reach the plant’s roots. 

This soil is ideal for most plants, including the walnut tree. Loam may be ideal, but it isn’t the only type of soil in which a walnut tree can thrive.

Sandy Loam

A soil described as a sandy loam has all three types of soil particles but has higher concentrations of large sand particles. Clay particles are present but in small quantities.

This soil will retain some moisture but drain quickly and prevent soil compaction under normal conditions.

Silt Loam

A soil described as a silt loam is at least fifty percent silty, with lower percentages of clay and sand. 

Silt loam has excellent water retention but drains thoroughly between rains, allowing oxygen to reach tree roots.

Clay Loam

A soil described as clay loam is less than 40 percent clay and 45 percent sand; the remaining particles are silt.

Clay loam retains more moisture than the other soils on this list, but the high percentage of sand still allows for thorough drainage. 

Walnut Trees Need Deep Soil

In addition to having suitable soil for your walnut tree, you will want to ensure you have enough of it. Walnut trees form a deep taproot with a wide-spreading root system. This root system needs a lot of room to grow in search of water and nutrients.

Walnut trees have a deep tap root that requires at least three feet of loose soil before hitting bedrock, dense clay, or gravel. 

If this deep tap root doesn’t have enough loose soil to grow into, your tree could die before it reaches maturity. Walnut trees need at least three feet of loose, fertile soil to become established. 

The Best States To Plant A Walnut Tree

Both black walnut trees grow naturally in the Eastern United States. Since English Walnut trees require similar growing conditions to black walnuts, they can be planted in the same locations. 

The best states for walnut trees:

• Maryland
• West Virginia
• Virginia
• North Carolina
• South Carolina
• Georgia
• Tennessee
• Lower Michigan
• Alabama 
• Mississippi
• Louisiana
• Arkansas
• North-eastern Texas
• Kansas
• Nebraska
• Iowa
• Southern Minnesota
• Southern Wisconsin
• Illinois
• Kentucky
• Tennessee
• Indiana
• Missouri

You can read more in our piece on the best places to plant a walnut tree!

The Best Climate for Walnut Trees

Walnut trees prefer a mild climate and cannot tolerate extreme heat or cold during the spring and fall. If the buds of the tree get hit with frost too early in the spring, your tree could end up damaged.

Walnut trees are sensitive to certain bacterial pests that are spread during times of early frost. Avoid planting your tree in any microclimate known for intense frost.

Walnut Trees Are Sensitive To Areas Of Drought

Similarly, walnut trees like to grow in moist soil. This makes them sensitive to hot areas because a drought could prematurely dry out the soil. 

Even though a walnut tree prefers moist soil, soil that is too wet can be just as damaging as soil that is too dry.

Walnut trees do not tolerate sustained flooding for three or more days. Prolonged flooding keeps oxygen and other essential nutrients from being absorbed by the tree roots.

Walnut trees do not grow well in the shade. They should be planted independently, so they don’t have to compete for sunlight.

At most, a walnut tree can tolerate some dappled shade but should get full sun for most of the day. It takes a lot of sunlight to grow those delicious nuts!

Best Locations To Plant A Walnut Tree

The common factor among the soil types described in the section above is the ability to retain water while also maintaining appropriate drainage so that the roots of your walnut tree get the oxygen they need. 

If you are unsure what kind of soil exists on your property, a few ecosystems are universally loved by walnut trees:

• Hardwood bottom lands
• Stream and river beds
• Low portions of north or east-facing slopes
• Low uplands
• Terraces

So if you’re aiming to plant a walnut tree – start with those spots!

Hardwood Bottom Lands

Hardwood bottomlands are forested wetlands near a river. These areas are characterized by periodic flooding, usually in early spring.

While hardwood bottomlands are excellent places for walnut trees, they can only withstand flooding for three to four consecutive days outside their dormancy.

Make sure your walnut tree does not have to endure flooding during the growing season. 

Stream and River Beds

Streams transport sediment-rich nutrients to be deposited along the bank down steam. Since walnut trees love rich, moist soil, stream, and river beds are excellent locations for walnut trees.

Similar to bottomlands, streams and riverbeds are prone to flooding, which can damage a walnut tree. Ensure the site for your walnut tree endures no more than three to four consecutive days of flooding in the spring. 

Low Portions of North or East-facing Slopes

Walnut trees grow well on north and east-facing slopes because these areas are not exposed to the hot afternoon sun.

These areas get sun early in the morning but remain shaded during the hot afternoon, ensuring the soil does not dry out. Walnut trees prefer moist soil with good drainage. 

South and west-facing slopes get a bulk of the hot afternoon sun baking the topsoil. This phenomenon may cause the soil to dry out quickly.

Dry soils compact more efficiently, and do not allow for excellent water drainage or nutrient accumulation. This may be a good spot for a heat-loving tree or plant, but just not perfect for walnut trees. 

Walnut trees need at least three feet of fertile topsoil to grow successfully. Higher portions of mountains or bluffs have shallow bedrock and are not great locations for walnut trees. 

Low Uplands

According to Purdue University, Uplands are the highest landscape parts, while lowlands are associated with rivers and streams.

Low uplands are the middle to lower portions of uplands where the topsoil is still deep enough to support a large walnut tree.

Low uplands make great locations for a walnut tree because the soil is rich in nutrients and relatively moist due to the drainage from higher portions of the landscape.

Terraces

Terraces are the in-between layers in a landscape, between the uplands and the floodplains. Terraces usually form from an ancient glacial upwash that deposited nutrient-rich soil. 

Soils that form from a previous outwash are well drained and deep enough for a walnut tree’s deep tap root, making them an excellent planting location. 

Tips For Long-Term Care of Walnut Trees

Now that you know the best soils and locations to plant your walnut tree let’s review some long-term care tips to ensure your tree’s long, healthy life!

Caring for your walnut tree after planting can include:

• Weeding
• Pruning
• Watering
• Fertilizing
• Pest management

Weeding

After you have chosen the perfect site for your walnut tree and planted the tree with the addition of rich compost, you will need to control weeds for the first three years after planting. 

This reduces competition for sunlight, moisture, and soil nutrients. It also reduces the likelihood of rodents making a home near your tree and possibly damaging the tree’s young bark. You can control weeds by mowing or applying a herbicide.

Pruning

Young walnut trees should not need to be pruned unless you notice dieback. These trees are sometimes susceptible to disease, so if you notice a small area of your tree is not doing well, it is okay to prune it off.

Walnut trees are naturally able to grow straight and upright. As the tree matures, some pruning is acceptable. Generally, you will want to let your walnut tree do its own thing. 

Always contact a professional if you are unsure how to prune a tree, or if you can’t tell what your walnut tree may need!

Watering

A healthy walnut tree planted in an appropriate location won’t need much watering through human intervention. The natural precipitation of the climate will provide plenty of moisture.

Newly planted walnut trees should be watered once per week along their drip line during their first growing season. Because walnut trees don’t like saturated soil, avoid watering too close to the trunk. After the first growing season, there is no need to provide supplemental water. 

Drought is becoming more of a common occurrence these days. If you experience an unexpected dry spell, water your walnut tree deeply once per week. Take care not to overwater. Walnut tree roots need to dry out to access oxygen in between waterings. 

Fertilization

If you have chosen the correct location for your walnut tree with moist, rich, well-drained soil, you will not need to fertilize your tree.

If your location isn’t among the four best walnut tree soils, you can fertilize with an organic, nitrogen-rich fertilizer such as Espoma Organic Tree-Tone.

Consult with your local arborist, or get your soil tested to find out what your soil may be lacking. Adding specific nutrients to the soil is better than guessing or adding too much fertilizer to your soil. 

Too much fertilizer may cause an overgrowth of weeds. Young walnut trees do not like to compete for nutrients!

Pest Management

There are a few significant pests of black walnut trees. The most common are walnut caterpillars, bud borrers, and cankers. You may need to apply insecticides or fungicides to combat these problems.

Always consult an expert before applying insecticides or fungicides to your new tree. In most cases, it is not necessary to use heavy chemicals on a single walnut tree.

Hot Tip! Managing Juglone

English walnuts and black walnuts produce a chemical compound in all parts of the walnut tree (black walnuts produce more than English walnuts.)

This component is called Juglone and can slow down certain plant species’ growth This is the primary reason why people don’t grow black walnut trees.

Not all plants are sensitive to juglone. The most affected are members of the nightshade family, such as tomatoes, potatoes, eggplants, and peppers. Some common landscaping shrubs like lilac and hydrangea are sensitive to this compound.

If you plan to plant your walnut tree near your garden, it is best to look up what plants can be safely planted with a walnut tree without inhibiting growth.

There are no known exhaustive lists of plants sensitive to juglone; so here are a few that we’re akin to!

Common Trees Sensitive To Juglone

• Alder
• Apple
• Birch
• Linden
• Hackberry
• Larch
• Magnolia
• Silver Maple
• Norway Spruce
• Pine

Common Shrubs Sensitive To Juglone

• Azalea
• Chokeberry
• Cotoneaster
• Hydrangea
• Lilac
• Viburnum
• Yew

If you notice your garden wilting, yellowing, or generally looking stunted, you may be experiencing a poor interaction with Juglone

The good news is that juglone breaks down quickly, so if you remove a walnut tree from your yard, you will only need to wait a few months before it is safe to plant in that space.

Remove the walnut tree, and wait one entire growing season. Your soil should be on its way back to normal but may take 5 years. For more information, check out our article about when to cut down your walnut tree!

Let’s Review!

Walnut trees are an excellent choice for many landscapes!

A Walnut tree can bring diversity, shade, and food to your yard! Walnut trees need nutrient-rich, moist, well-drained soil. They must be planted in at least three feet deep topsoil to allow room for the tree’s deep tap root. 

Knowing the right location for a walnut tree will ensure you have a beautiful tree to appreciate for many years to come!

Best of luck on your tree-planting journey!

References:

Desta, F., Colbert, J. J., Rentch, J. S., & Gottschalk, K. W. (2004). Aspect induced differences in vegetation, soil, and microclimatic characteristics of an Appalachian watershed. Castanea, 69(2), 92-108.

Islam, A. M., & Widhalm, J. R. (2020). Agricultural uses of juglone: Opportunities and challenges. Agronomy, 10(10), 1500.

Michler, C. H., Woeste, K. E., & Pijut, P. M. (2007). Black walnut. In Forest trees (pp. 189-198). Springer, Berlin, Heidelberg.

Ponder, F. (2004). Soils and nutrition management for black walnut. UNITED STATES DEPARTMENT OF AGRICULTURE FOREST SERVICE GENERAL TECHNICAL REPORT NC, 243, 71.

Strugstad, M., & Despotovski, S. (2012). A summary of extraction, synthesis, properties, and potential uses of juglone: A literature review. Journal of Ecosystems and Management, 13(3).

You may consider planting a black walnut tree for many reasons. They are attractive, provide plentiful shade, have few pest issues, produce an edible nut, and some people are even interested in the high valued lumber that can be harvested from black walnut trees. However, there are several reasons not to plant a black walnut tree in your yard which you should also carefully consider. 

Black walnut trees produce juglone, which is present in all parts of the tree. Juglone is produced by the black walnut as a way to keep other plants from competing with it. Juglone can also eliminate other plants, including several plants you may have in your home garden or landscape.

There are several other factors which make black walnut an unappealing choice for a shade tree in your yard. In this article, we will cover all of the drawbacks of planting a black walnut tree as well as how you can remove one from your property.

What Is A Black Walnut Tree?

Black walnut trees are in the genus Juglans along with other trees such as butternut and English walnut (which is what you buy at the grocery store to eat).

This is an image of a black walnut tree at our family property during the Fall. There’s a younger black walnut growing next to it, but the large when is a mature black walnut tree.

You can tell it’s a black walnut tree by noticing some of the remnants of the leaves in their distinct leaflet orientation, which I’ll get into a bit later!

In this section, we will tell you about the etymology, how to identify a black walnut tree, and uses for black walnut trees. Let’s get to it!

Etymology: The Meaning Of The Scientific Name For Black Walnut

Etymology is the study of the origin of words and how their meaning has changed over time. When it comes to the etymology of scientific names, this typically means deciphering their Latin meaning.

The scientific name of a species is made up of two parts, the genus (which is capitalized) and the specific epithet (which is lower case).

For example, all walnut trees are in the same genus Juglans, but each species has its own unique specific epithet such as nigra to distinguish it from other members of the same genus.

The meaning of the scientific name for black walnut, Juglans nigra, is black nut of Jupiter.

Juglans is a combination of the Latin word Jupiter, referring to Jupiter (god of the sky), and glans, meaning acorn. This likely refers to the fact that walnut trees can grow quite large and produce an edible nut.

How To Identify A Black Walnut Tree

Black walnut trees are characterized by having an overall form with a straight trunk and open canopy. It can grow as tall as 120 feet but averages 50 to 70 feet tall and 50 to 70 feet wide.

Black walnut has pinnately compound leaves which have a central petiole known as the rachus and leaflets which grow on either side of the rachus. The leaves have anywhere from 9 to 23 leaflets which are just under a half foot long and about 2 inches wide. The leaflets have a serrated toothlike margin and are hairy on the underside. 

The bark is a grayish-brown to black color and mature trees have bark with ridges which form a roughly shaped diamond pattern. 

Black walnut trees have both male and female flowers and are primarily wind pollinated. The male flowers are yellow-green catkins, a slim, cylindrical spike, which hang down in clusters. The female flowers are white and form spikes usually in pairs. 

The fruits of black walnut trees form from the female flowers after pollination in fall, usually in pairs.

They are around 2.5 inches wide when mature and covered in a thick green husk which contains juglone, a black walnut specific chemical to protect the inner nuts from predators. Beneath the husk is a hard shell, which contains the nut, and is dark brown to black in color.

We have many black walnut trees across our property spread across naturally in wooded areas – here’s a black walnut fruit example of a fallen fruit I took during the summer.

One thing about black walnuts is that they have quite the pungent smell to them which is typically thought to be the juglone giving off its signature scent to tell pests and insects to ‘stay away‘.

Oregon State University provides some nice photos of the characteristics that distinguish black walnut trees from other walnut trees if you’d like some more specifics.

Uses Of Black Walnut Trees

Black walnuts are edible and have a bold flavor when compared to the English walnuts which you typically find at the grocery store. You can purchase black walnuts online if you can’t find them at your local store. We love Hammons Black Walnuts which are wildly sourced and hand harvested. 

Black walnut is used for making high quality furniture and is favored for its dark, rich brown color.

Many other woods will be covered with black walnut veneer to reduce the cost of the furniture while still giving it the beautiful finish of black walnut. It is also naturally resistant to decay and insect damage. 

The juglone present in black walnut has a yellow-brown color which is used for dying clothing and other textiles.

It has also been used as a coloring agent in foods, cosmetics, and hair dye. It will also stain your hands if you remove the protective husks from black walnut fruits!

Where Do Black Walnut Trees Grow?

Black walnut trees are native to Eastern North America and grow well in hardiness zones 4 through 9. Their natural range extends in the north from Vermont through southern Ontario and west to South Dakota and in the south from Georgia through the Florida panhandle and westward over to eastern Texas. 

The USDA Forest Service provides a county-level map of the native range of black walnut.

Black walnut trees have been introduced to more than 14 countries, most of which are in Europe. It has also been introduced to Mexico, and a few countries in South America and minimally in Australia. 

Outside of its native range, black walnut trees are most abundant in Europe and western North America. 

Let’s dive into the 5 reasons you should NOT plant a black walnut tree!

Juglone Will Effect Other Plants In Your Yard

Juglone is a allelopathic compound produced by all plants in the family Juglandaceae. It is considered a defense mechanism. Plants use it to eliminate plants in the nearby vicinity, reducing competition for sunlight, nutrients, and water.

Juglone does begin to break down when it contacts air, which is why we can eat its nuts and use it to make furniture without encountering the negative effects. 

Black walnuts have higher concentrations of juglone than any other tree, and it is present in all parts of the plants.

Juglone concentrations in the roots are highest throughout the growing season, and it can contaminate soil as far as 60 feet away from the adult tree!

The hulls of the fruits also have very high concentrations of juglone to help deter animals from eating the nuts so they can survive and form new trees. 

Juglone can stain clothing and your hands with a yellow-brown stain. This staining property is why juglone has been used as a dye for clothing and for coloring in food, cosmetics, and hair dye. 

Juglone can impact several plants in your garden such as peppers, tomatoes, and eggplants. It can also eliminate plants in your landscape such as rhododendrons and azaleas. Further, it can impact other trees on your property such as crabapples, silver maples, and pines. 

For an extensive list of plants not to grow under your black walnut tree, check out our list of 20 plants not to grow under a black walnut tree.

Thousand Cankers Fungus (TCD)

TCD is caused by the fungus Geosmithia morbida, which was first recognized in 2008 as the cause of damage to walnut trees which had been occurring since the 1990s.

The fungus is carried by a tiny bark beetle, the walnut twig beetle (Pityophthorus juglandis), which infects the tree when it begins feeding. 

By the time TCD was recognized as the cause of walnut tree dieback, it was already spreading throughout the western United States. It was first detected in the eastern United States, the native range of black walnut, in 2010.

The Missouri Department of Agriculture provides a map showing the current spread of TCD in the United States. 

Trees with TCD will show signs such as yellowing and wilting of foliage. Beneath the bark, thousands of cankers form and ultimately girdle the tree, preventing nutrients and water from moving throughout the tree.

Though it takes several years, TCD ultimately leads to the demise of the infected tree. 

If you live in an area where TCD is present, this is another significant reason not to plant black walnut trees. You don’t want to waste time growing a beautiful shade tree just to see it meet its demise from TCD.

Pests And Insects Love Black Walnut Trees (Even With Juglone!)

Even if your black walnut tree does succumb to TCD, there are many other insects and fungi which can cause injury to the tree and decrease its aesthetically pleasing appearance. 

Both Powdery mildew (Phyllactinia guttata) and Anthracnose (Gnomonia leptostyla) are fungi which impact black walnut causing leaves to become discolored and fall from the tree early.

Anthracnose can also damage the stems and the fruit of black walnut, decreasing the quality and edibility of the nuts. 

Crown gall (Agrobacterium tumefaciens) impacts the roots and root crown of black walnut causing light colored bulges. Damage can lead to stunted growth and rarely the loss of the tree. 

There are also several species of eriophyid mites that cause galls to form on black walnut trees when they feed on the tree. Galls are abnormal growths which can come in many shapes and sizes depending on which mite species creates them. Galls can cause discoloration and distortion of the stems and leaves, and some also cause lower fruit yield.

The University of Missouri discovered three new mite-induced galls on trees in Missouri as recently as 2015. So there could be even more mite-induced galls on black walnut trees which remain to be discovered in the future!

Black Walnut Trees Are Very Messy

Sure, all deciduous trees require cleanup when they lose their leaves in the fall. However, there are a few factors that make the cleanup from black walnut trees more difficult than your typical shade tree.

Cleaning Up The Leaves

First of all, their leaves can quickly multiply in your yard as they begin to break down. Since black walnut trees have pinnately compound leaves, each leaf actually has up to 23 leaflets. This gives black walnut leaves the potential for a single leaf to turn into 23 leaves when the leaflets start detaching from the rachus. 

You’ll also have to think about where to put all of those leaves.

Since the black walnut leaves do contain the chemical juglone, you have to compost them for long enough to let the juglone decompose so your compost doesn’t eliminate the plants you use it on.

Keep this in mind if you plan to add the leaves to your usual compost pile.

Due to the juglone in the black walnut leaves, you’ll also want to keep them from blowing all over your property or the juglone could blow around, causing problems for plants in areas you thought were far enough away from the tree to prevent juglone effects.

Cleaning Up The Fruit

The fruit from black walnut will also create a mess for you to clean up in fall. Black walnuts are slightly smaller than a baseball and have a soft outer shell called the hull which encases the hard shell which protects the nut in the center. 

As the fruit decays, the hulls will separate from the shells, multiplying the mess the fruit will make after they fall. If squirrels get involved and extract the nuts from the hard outer shell, your mess multiplies even further as each fruit is broken down into multiple pieces for you to clean up. 

A healthy mature black walnut tree can produce up to several hundred pounds of black walnuts per year. That is a big mess for you to clean up, especially if you have a healthy, well-producing tree!

Not to mention when the fruit falls, it could easily act like hail towards any structures on your property. Yikes!

Just like the leaves, fruits of black walnut also contain juglone, with the hulls having the highest concentration of any part of the tree.

You’ll want to carefully consider where you dispose of the fruit you clean up to prevent spreading juglone to other parts of your property.

Mature Black Walnut Trees Are Quite Large

The black walnut is a fast-growing tree. Once established, black walnut trees can gain 12 to 24 inches in height each year. On average, black walnut trees can grow to be 50 to 70 feet tall and 50 to 70 feet wide. Wild black walnut trees can grow over 100ft with optimal growing conditions!

The size of a mature black walnut tree can cause issues in your lawn, even though most grasses are resistant to juglone, by shading out sunlight and competing for water and nutrients. 

A mature black walnut tree reaching a height of 70 feet and width of 70 feet will ultimately create an area of at least 4900 square feet where plants susceptible to juglone effects won’t be able to grow. That’s a pretty large area to create in your yard where you won’t be able to plant species which are sensitive to juglone!

How To Get Rid Of Black Walnut Trees

So, if you have a black walnut tree – here are a few ways to get rid of it in your yard.

If you’re not sold on chopping down that black walnut tree yet, take a look at our piece on the reasons to cut down your walnut tree which specifically reviews black walnut trees!

Mechanical Control

Mechanical control means removing the plants using a mechanical method such as mowing them down with a lawn mower or cutting them down with a chainsaw. 

If you’re dealing with newly emerging black walnut trees, either saplings from seeds or root sprouts from an adult tree that’s been removed, you can mow these down if there is a large number of them. If there are only a few, it is better to pull saplings up by the root to keep any root sprouts from occurring.

Follow up mowing with a chemical application, described below, to make sure the roots don’t remain living in the soil which could cause more root sprouting.

If you’re dealing with a mature black walnut tree, it is best to consult a professional about removal. Removing any full grown tree should always be handled by a professional.

We recommend you use a certified arborist to ensure the job gets done right!

The best time to cut down your walnut tree is when it is dormant during the winter and early spring. A freshly cut tree can attract bark beetles to the area, which could end up feeding on nearby trees that you want to keep. A tree without leaves can also make an arborist’s job of removing it easier.

Of course, if there’s issues your black walnut tree is causing then it should be taken down ASAP.

Chemical Control

Chemical control is what it sounds like: controlling an unwanted pest with the use of a pesticide. In this case, black walnut trees are the pest and you’ll use an herbicide to remove them.

Once the mature tree is removed, it is a good idea to immediately apply an herbicide such as glyphosate to the tree stump to help prevent root suckers and stump sprouts from forming if any growable black walnut remains. We like this Concentrated Weed & Grass Killer which has 41% glyphosate. 

Anytime you use herbicides, make sure to follow the directions carefully to prevent harm to yourself and the environment.

Make sure to keep an eye on the area where the black walnut tree was growing and take care of any saplings or root suckers as soon as you see them.

Saplings can be easily removed by hand, but make sure you wear protective gardening gloves. Root suckers can be treated with an herbicide like glyphosate. 

Remember, don’t immediately start planting juglone sensitive plants after removing your black walnut tree. It can take up to 5 years for the roots to decay and the juglone to disappear completely from the soil!

Your arborist will know best!

That’s All We’ve Got!

Black walnut trees can be beautiful, native shade trees in the landscape. They have many uses from being edible, making high end wood furniture, and as dye for textiles. 

However, there are some drawbacks to planting black walnut trees on your property. 

The juglone they produce can negatively impact other plants including certain vegetables, ornamental plants, and other trees on your property.

There are also several insects and fungi which can impact the health of black walnut, some of which can lead to its ultimate demise. Black walnut trees also make quite a mess in your yard in the fall and will grow quite large.

We recommend you consult a professional if you already have a black walnut tree you want to remove from your property. Make sure you follow up with the proper pesticide to keep root suckers from growing back. 

If your heart is still set on having a walnut tree in your yard, depending on where you live, you might consider an alternative such as English walnut which has some similar characteristics as black walnut but doesn’t produce as much juglone. 

If you’re interested in finding out if an English walnut tree might be an alternative for you, check out the 5 Best Places To Plant A Walnut Tree (And How To Do It) which provides details on where you can plant an English walnut tree!

Reference

Hejl, A.A., Einhellig, F.A. and Rasmussen, J.A., 1993. Effects of juglone on growth, photosynthesis, and respiration. Journal of Chemical Ecology, 19(3), pp.559-568.

Michler, C.H., Woeste, K.E. and Pijut, P.M., 2007. Black walnut. In Forest trees (pp. 189-198). Springer, Berlin, Heidelberg.

Rietveld, W.J., 1983. Allelopathic effects of juglone on germination and growth of several herbaceous and woody species. Journal of Chemical Ecology, 9(2), pp.295-308.

Tisserat, N., Cranshaw, W., Putnam, M.L., Pscheidt, J., Leslie, C.A., Murray, M., Hoffman, J., Barkley, Y., Alexander, K. and Seybold, S.J., 2011. Thousand cankers disease is widespread in black walnut in the western United States. Plant Health Progress, 12(1), p.35.

If you have one of those gorgeous, large, otherworldly black walnut trees in your yard, chances are at one point or another you’ve thought about cutting it down. Believe me, you aren’t the only one! We understand, and there are a few good reasons as to why you’re thinking that way.

Here are the best reasons to cut down your black walnut tree: Other plants can’t grow around it, it has surface roots, it requires too much upkeep, branches are too close to your property, to minimize storm damage, or the tree is dying and browning.

Although walnut trees are beautiful, we’ll dig deeper into the reasons you might want to cut down your walnut tree, and just when you should do it. Keep reading to learn more!

Your Walnut Tree Is Excreting Chemicals

There are many reasons in which you may want to cut down your walnut tree. Although some of them may not apply to you, it is good to know some common ones to understand the effects this tree can have.

If you want to keep a walnut tree maintained, consider using something like this Sun Joe Pull Chain Saw. It’s electric and can give you a bit more of a boost to get those high up branches with ease!

If you still think you may want to cut the tree down, keep on reading!

Also, please keep in mind that we are referencing black walnut trees below, as english walnut trees do not primarily grow in the United States while black walnut trees do!

Juglone In Black Walnut Trees

There’s a scientific reason other plants can’t grow around your black walnut tree. Black walnut trees contain a chemical toxin called juglone.

This chemical is exuded from all parts of the tree. This chemical is not unique to the black walnut tree, and other species that contain juglone are other walnuts, butternut, pecan, and hickories.

However, what is unique to black walnuts is that they contain the highest amount of this chemical compared to other trees.

Juglone is spread throughout the entire tree and deposited into the soil making it inhabitable for certain plants to survive.

You can view our full list of plants not to plant under a black walnut tree here.

There are certain shrubs and herbaceous flowers that can grow under black walnut trees. These includes daffodils, daylilies, ferns, irises, forsythias, yarrow, astilbe, phlox, tulips, hostas, bee balm, rose of Sharon, St. John’s Wort, and barberry.

Certain trees are also tolerant to juglone including maples, eastern red cedar, serviceberry, sweetgum, oaks, and dogwood to name a few. But for trees, the list is quite long.

Moreover, some vegetables and fruits are tolerant to juglone, too! This includes onions, beets, squashes, carrots, beans, corn, cherries, plums, and peaches.

If none of these plants suit your needs and you’re struggling to grow anything in your yard, then you might consider removing your black walnut tree.

If you want to learn more about your black walnut, you can check out our article on the main difference between walnut trees and black walnuts trees here!

Your Black Walnut Tree Has Surface Roots

Surface roots are a real pain in the butt, especially if you have lots of them. If you’ve noticed surface roots for a while stemming from your tree, it could be that your tree has struggled to find the nutrients it needs. 

Surface roots are dangerous to have on your lawn. Your tree is also more susceptible to animals, weather, and damage with showing roots. 

Surface roots aren’t always something that can be removed. And removing them could do more harm than good to the tree. In this case, it might be recommended that the entire tree comes down rather than trying to remove pesky roots. 

If this is the case, we suggest calling tree professionals to check it out and determine the best thing to do.

Your Black Walnut Requires Too Much Upkeep

If you’ve ever been around a black walnut, you know how much of a tripping hazard it can be. The black walnut husks are about the size and color of a tennis ball and fall with force to the ground. Seriously, it sounds like someone is throwing baseballs onto the ground from up in a tree!

Despite their bright green color, these husks are incredibly easy to trip on and can be more of a nuisance than anything. 

When black walnut husks begin to fall, it seems like they never stop! The upkeep of black walnut trees might be more than you bargained for. 

As we mentioned above, because certain plants can’t grow around black walnuts, this could create a barren lawn that you didn’t necessarily want. So between the upkeep and barren ground, you might be considering taking down your tree. 

Your Black Walnut Is Producing Too Much Juglone

Black walnuts produce the chemical juglone, which we briefly touched upon above. Juglone becomes a toxin when pre-juglone from within the tree is oxidized. So when any sort of cut or damage happens to the tree and pre-juglone is exposed, that’s when it becomes oxidized and turns into juglone.

Because it is found in all parts of the tree, consuming too many black walnut leaves or using walnut shavings as bedding can cause issues with animals. 

Now, we don’t think you’re going to be eating black walnut trees or using the pine shavings as bedding! But if you have dogs, horses, goats, etc., you’re probably considering them in this too. Because if you’ve had any animals, you know that they like to get into trouble.

Juglone isn’t just an issue for humans, it’s also an issue for animals and livestock. According to the Ontario Ministry of Agriculture, Food and Rural Affairs, juglone sensitivity in equines is extremely high and can cause laminitis within a few days of exposure when present in bedding.

Some people are more sensitive to juglone than others, which can result in a reaction when near it. If you are concerned about this we recommend contacting tree professionals to give you the rundown about your black walnut tree, juglone, and what to do!

To Minimize Potential Storm Damage From Branches

Is your tree growing too close to your house? Is it in a questionable area? This could be leading you in your decision to cut down your black walnut

If you live in an area where hurricanes are an issue, you may be wanting to cut down your walnut tree too

If you want to cut down your tree because of hurricane winds, don’t! According to North Carolina State University, in category three hurricane winds, most trees are not going to fall. Some trees can prevent more damage by blocking winds.

However, if you see that your tree has some rough spots that look like they could be laden with pests or infections, then cutting down your tree to minimize potential storm damage could be the right move for you.

Additionally, some storms have more significant winds than hurricanes, and if you have a tree that stretches to your home, or is even close to it, well then your best bet might be to cut it down, especially if it’s considered an overly mature tree.

Want to learn more about cutting down your tree? You can check out our general guide on the main reasons to cut down a tree in the front of your house!

Your Black Walnut Tree Is Susceptible To Pathogens

Black walnut trees are susceptible to a complex invasive pest problem called thousand canker disease. This disease needs the walnut twig beetle and a pathogen to take down these massive trees.

The craziest thing is that the walnut twig beetle carries the spores of the tree fungal pathogen Geosmithia morbida, which is responsible for thousand canker disease in black walnut trees according to Clemson University.

So when the walnut twig beetle bores beneath the surface of the bark, they can spread this fungal pathogen!

As a result, cankers form from the surface where the beetle bored into. The combination of the boring beetles and cankers, over time, will end the tree.

Your Black Walnut Tree Is Showing Signs Of Stress

This goes hand in hand with the things we mentioned above. Is your tree looking stressed out? Rough-looking branches, losing leaves, noticeable damage signs? If so, your tree might be stressed out and it might be on its way out anyway.

There are certain things to look for to tell if your tree is stressed out including, canopy dieback, cracking and splitting in the trunk, leaf drop, wilting and brown leaves, and even mushrooms near the base of the tree.

• Canopy dieback is exactly what it sounds like. This is usually when parts of the tree’s canopy begin dying, losing leaves, and branches die.
  
• Cracking and splitting in the trunk is typically an issue. This can be caused by poor wound healing and when weak branches split. If the tree doesn’t heal itself it can indicate a distressed and unstable tree.
  
• Leaf drop does not always mean your tree is on its last leg. If your tree is dropping leaves, it could be a result of drought stress or overwatering, however, it can also be due to disease or an infestation.

So if you notice leaf drops accompanied by other things, it’s probably best to contact professional arborists to help determine the root cause.

Additionally, if you notice wilting and brown leaves on your tree it could be a response to heat stress and the sun, but if this is a newly planted tree, it could be in shock.

Either way, your tree is stressed out! You can try watering your tree at least once a week and apply mulch to its base. If these don’t work, then you might have a bigger issue on your hands.

When you see mushrooms growing near the base of your tree, it’s never a good sign. This typically indicates issues with the roots or the trunk. 

It could be anything from root rot, which is exactly what it sounds like, to heart rot, which is where the interior wood of the tree decays, and even the overall rot of the entire tree. 

So, if you see many mushrooms at the base of your tree, we suggest calling tree professionals ASAP!

When To Cut Down Your Walnut Tree

Whether you’ve had it up to here with your black walnut tree, or you notice signs of stress, then it might be time to cut your walnut tree down. 

Depending on what’s going on with your tree, that can determine when you’re going to cut it down. If removing your tree is dire (branches too close, tree looks like it will fall, etc) then most likely a tree company will remove it ASAP.

If it’s something that can wait, then the best time to cut down your walnut tree is in the dormant season, which is between late winter and early spring!

That’s A Wrap!

While you may or may not love your black walnut tree, it may be time to cut it down. Let’s recap!

These are the most common reasons people cut down their black walnut tree: 

• Other plants can’t grow around it
• Your tree has surface roots
• It requires too much upkeep
• It’s a hazard to you
• To minimize storm damage
• It’s susceptible to pathogens
• It’s showing signs of stress.

If you decide to cut down your black walnut tree, depending on the reasoning will vary throughout the year, however, the most typical time to cut it down is during the dormant season.

During the dormant season, your tree has no leaves making it easier to cut and handle.

If your tree needs to come down ASAP, a professional arborist will make the call on when it’s best to cut your tree down.

Thanks for sticking around and learning about why to cut down your walnut tree, and when to do it! Until next time!

References

Cline, Steven, and Dan Neely. “Relationship between juvenile-leaf resistance to anthracnose and the presence of juglone and hydroquinone glucoside in black walnut.” Phytopathology 74, no. 2 (1984): 185-188.

Coder, Kim D. “Seasonal changes of juglone potential in leaves of black walnut (Juglans nigra L.).” Journal of Chemical Ecology 9, no. 8 (1983): 1203-1212.

Ponder, Felix, and Shawky H. Tadros. “Juglone concentration in soil beneath black walnut interplanted with nitrogen-fixing species.” Journal of Chemical Ecology 11, no. 7 (1985): 937-942.

Schmidt, S. K. (1988). Degradation of juglone by soil bacteria. Journal of chemical ecology, 14(7), 1561-1571.

Von Kiparski, G. R., Lee, L. S., & Gillespie, A. R. (2007). Occurrence and fate of the phytotoxin juglone in alley soils under black walnut trees. Journal of Environmental Quality, 36(3), 709-717.

Walnut trees are well-known for their tasty fruit – the walnut! These trees are excellent ornamental trees that provide plenty of shade and will attract wildlife. If you’re thinking about planting one, you may be wondering where the best place to plant a walnut trees is?

The most common walnut trees include the black walnut and the English walnut. Black walnuts can grow in hardiness zones 4 through 9, while English walnuts prefer zones 3 through 7. The most popular states to grow walnut trees includes California, Illinois, Iowa, Indiana, Minnesota, and Missouri.

California is the United State’s largest producer of walnuts, but that doesn’t mean walnut trees can’t grow in other places, too! Below, we’ll check out the best places to plant a walnut tree and how to plant them.

Where Should I Plant A Walnut Tree?

English walnuts are the more popular walnut tree if you are looking to harvest the nuts. The shells are far easier to open than black walnut. But if you’re not concerned with the walnut fruit and just want a nice-looking shade tree, either walnut will do just fine!

Both walnuts prefer full sun and moist, well-drained soils where they can establish a deep taproot. Black and English walnuts prefer clay, sand, or loam soils with a neutral PH. 

Walnut trees are renowned for their production of a natural herbicide called juglone. When planting a walnut, don’t expect much else to grow around it. You can view a list of plants that you should specifically not plant around a walnut tree here.

English walnuts are a little more tolerant of the cold than black walnuts, but not by much. Both trees are susceptible to late spring frosts, which can put a serious damper on fruit production and growth.

When deciding where to plant a walnut tree in your yard, make sure you have plenty of room. According to North Carolina State University, English walnuts can grow up to 60 feet and black walnuts can reach heights of 75-100 feet. 

You’ll also want to be careful about juglone exposure – Don’t plant a walnut tree near your garden!

Can I Plant A Walnut Tree Anywhere?

Walnut trees can be planted almost anywhere in the United States. The few exceptions would be areas that are either too cold or too hot for walnuts to survive.

Walnuts don’t survive well in the cold areas of Alaska that dip below -40℉ in the winter. On the other end of that extreme would be areas like southern Florida, Texas, Arizona, and southwest California that are just too hot to grow walnut trees. Most of the Hawaiian Islands are also too hot to grow walnut trees.

Walnut trees cannot be planted in shade and they will not do well in wet soil. Otherwise, walnuts are pretty content to be planted anywhere. You can always check the USDA Hardiness Zone Map to make sure your area will support walnut trees.

5 Best Places To Plant An English Walnut Tree

English walnut trees, also called Persian walnuts, are more popular for planting than black walnuts. As mentioned before, English walnuts thrive in hardiness zones 3 through 7.

For optimal growth, you’ll want an area that has a combination of the right temperature, plenty of sunlight, and the right soil type.

So, let’s take a closer look at the states within these zones and discuss the best places to plant an English walnut tree.

If you’re still confused between the two primary walnut tree species, you can learn more about black and english walnut tree differences here.

Where To Plant English Walnuts In The West

The West is known for being drier and hotter than other regions in the U.S. There are some pockets of decent growing conditions for English Walnuts, but much of the west coast is too warm or sandy for English walnut trees.

Walnut trees can grow in any state in the west:

• Washington
• Oregon
• California
• Nevada
• Idaho
• Montana
• Wyoming
• Colorado
• Utah

However, some areas are better than others for growing English walnut trees, and a few regions of these states cannot grow walnuts because it is simply too hot or the soil conditions are not favorable.

The West includes a range of hardiness zones from 3 to 11. Hardiness zones define what the minimum temperature in that region can reach and are helpful when determining if your chosen tree can survive the winter or not.

In the West, optimal growing areas will be along with eastern Washington and Oregon, central and eastern California, northwestern Utah, western Colorado, and north- and southwest Idaho.

Even within these regions, there will still be some areas that aren’t optimal for English Walnuts due to soil conditions or drought. 

Where To Plant English Walnuts In The Southwest

The southwest is a large area of the United States but it only encompasses four states:

• Arizona
• New Mexico
• Texas
• Oklahoma

Many areas of this region include hot climates with dry, desert conditions. These are not optimal growing conditions for an English Walnut tree. 

In the Southwest, English walnut trees can grow well in central Texas and the Texas panhandle, and all of Oklahoma except the extreme southeast corner.

Where To Plant English Walnuts In The Midwest

The midwest is known for the corn belt and is America’s heartland. The weather and soil profiles vary greatly in the midwest region, and not all areas are good for growing English Walnuts.

The midwest includes:

• North & South Dakota
• Nebraska
• Kansas
• Minnesota
• Indiana
• Missouri
• Wisconsin
• Illinois
• Iowa
• Ohio
• Michigan

Although English Walnuts can grow in all of these states, optimal growing areas are going to be from southern South Dakota across to southern Wisconsin and northern Illinois. 

Kansas, Missouri, and Indiana have decent growing conditions across the state as long as the soil conditions are right. Much of Ohio and Michigan are suitable for English Walnuts as well. 

The northern regions of Minnesota and North Dakota can support English Walnuts, but the cold winters and late frosts can stunt growth and cause trees to produce less fruit.

Where To Plant English Walnuts In The Southeast

The southeastern United States is typically humid and can range from lowland swamps to the Appalachian Mountains.

The southeast includes:

• Arkansas
• Louisiana
• Mississippi
• Alabama
• Georgia
• Florida
• North & South Carolina
• Tennesse
• Kentucky
• Virginia
• West Virginia
• Maryland
• Deleware
• Washington D.C.

Many of these states are too warm to support healthy English Walnut growth. For example, Louisiana, most of Mississippi, and all of Florida are out of the English Walnut’s preferred hardiness zone.

Only the extreme northern regions of Mississippi, Alabama, Georgia, and South Carolina can support English walnuts.

Optimal growth is more likely to occur in Tennessee, Kentucky, West Virginia, and Virginia. Central and northern Maryland can also support good English Walnut tree growth.

Where To Plant English Walnuts In The Northeast

The northeast is known for displaying some of the most stunning fall foliage in the country. Both English walnut and Black walnut are deciduous trees that change color in the fall and drop their leaves in preparation for winter.

The English walnut boasts golden yellow leaves in the fall and feels right at home in many of the northeastern states.

Because of their proximity to the great lakes, some parts of the northeast tend to be gray most of the year, which can limit fruit production and growth for English walnuts who prefer lots of sun.

The northeast includes:

• Pennsylvania
• New York
• New Jersey
• Connecticut
• Rhode Island
• Massachusetts
• New Hampshire
• Vermont
• Maine

In the northeast, optimal growing areas for English walnuts includes all of Pennsylvania and Massachusetts, southern, central, and western New York, central New Jersey, northern Connecticut and Rhode Island, and central and southern Vermont, New Hampshire, and Maine.

Like the midwest, the northeast is susceptible to late frost in the Spring and early frost in the Fall which can stunt growth and lower nut production.

Vermont, New York, and Connecticut are the cloudiest states in the northeast and may not be the most optimal place to grow an English walnut. Nonetheless, these stately trees will still grow there and provide shade for those rare sunny days.

In most environments, walnut trees can produce up to 80 pounds of unshelled walnuts each year!

5 Best Places To Plant Black Walnut Trees

Black walnut trees are a little less popular than English walnut trees, but they are still beautiful trees that provide plenty of shade on those warm summer days.

Compared to English walnuts, black walnut trees typically thrive in warmer conditions. Their hardiness zone boundaries are between zones 4 and 9. 

Let’s check out the regions mentioned above and find out the best places to plant black walnut trees.

Where To Plant Black Walnut Trees In The West

Because black walnut trees overlap with much of the English walnut tree’s habitat, we’ll discuss the major differences between the two in this section.

Black walnut trees can thrive in almost all areas along the west coast except for a few hot spots near San Francisco and Los Angeles. All of Washington and Oregon are suitable for black walnuts as long as the soil conditions are favorable. 

Western Idaho, northern Nevada, and most of Utah will support black walnut trees, as will eastern and western Colorado. 

Much of Montana and Wyoming are too cold to support black walnut trees.

Where To Plant Black Walnut Trees In The Southwest

The southwest is a difficult place for many plants to grow due to the hot, dry conditions as well as the high elevation areas.

Black walnut trees can survive further south into Texas but do not reach the actual southern tip of Texas. Northeastern Arizona and nearly all of New Mexico and Oklahoma will support black walnut growth.

Northern New Mexico, Oklahoma, and the Texas Panhandle are probably the most optimal areas to grow black walnut trees in the southwest.

Where To Plant Black Walnut Trees In The Midwest

Much of the northern midwest gets too cold in the winter for black walnuts to grow to their full potential. For example, Northern North Dakota, Minnesota, and Wisconsin are simply too cold.

Southern Nebraska, Iowa, and Michigan have optimal temperature needs for black walnut trees. Kansas, Missouri, Illinois, Indiana, and Ohio also have good growing conditions as long as the soils are deep and well-drained.

Where To Plant Black Walnut Trees In The Southeast

For English walnut trees, much of the southeast was simply too warm for the tree to thrive. Because black walnut can withstand warmer temperatures, they can dip a little further into the southeast than the English walnut.

But just because it can survive doesn’t mean it will thrive in these conditions. 

In the southeast, black walnuts grow optimally in Arkansas, Tennessee, Kentucky, West Virginia, Virginia, Maryland, and Deleware. They’ll also grow in northern Louisiana, central and northern Mississippi, Alabama, and Georgia.

In Florida, black walnuts can grow as far south as the Placid Lakes, but this is not their optimal growing zone as the temperatures are on the brink of being too warm for black walnuts.

Where To Plant Black Walnut Trees In The Northeast

The northeastern United States gets some of the strangest weather due to the Great Lakes. With so much varying weather conditions and patches of extremely cold temperatures, much of the northern northeast is off-limits to black walnuts.

Optimal growing areas in the northeast include all of Pennsylvania, New Jersey, Connecticut, and Rhode Island. Southern New York and Maine, and southeastern New Hampshire can also support optimal black walnut growing conditions.

How Do I Plant A Walnut Tree?

If you have the time and patience, planting a walnut tree from seed is better than transplanting it from a nursery. 

The reason is that walnut trees have deep taproots that grow straight down into the soil. This makes them more difficult to successfully transplant than a tree with more horizontally-growing roots.

Using local seeds dropped by local walnuts is the BEST way to plant a walnut tree. These seeds will already be accustomed to the area’s soil conditions and climate, meaning they will have the best chance of surviving.

Purchasing online seeds or plants is not recommended as these can be from vastly different regions. The tree will grow, sure, but it won’t grow as fast or produce as much fruit as a local seed will.

Even if you find and use seeds from local walnut trees, using fertilizers can be helpful as nut trees need as much nitrogen as they can get. Using something like J R Peters Jacks Classic All Purpose Fertilizer can help your walnut tree thrive as it grows.

Make sure your seeds are viable by dropping them in water. The ones that float can be discarded. The best time to plant your seeds is in the fall. Push them 1-2 inches into the soil. By Summer you should notice some growth out of the soil.

It’s recommended to protect your vulnerable saplings from wildlife by using a tree protector. Andwarmth’s Tree Protectors come with six tree protectors that can be added together to create wider or taller protection so you can continue to guard your walnut tree as it grows.

This is helpful especially once your tree begins producing fruit. The nuts will attract wildlife and can encourage deer to rub against the trunk or nibble on twigs in the winter.

That’s All For Now!

Walnut trees are more than just nice ornamental landscaping trees. They provide tons of shade on hot summer days and encourage wildlife like deer and squirrels to stop by.

Walnut trees require plenty of sun, deep, well-drained soil, and plenty of space to grow. Black walnuts and English walnuts are the two most popular walnut trees. They can survive in a variety of conditions, but each has its preferences.

This article was mainly focused on temperature requirements, but the soil is also an important factor in choosing the right location to plant a walnut tree. Walnuts prefer deep, well-drained soil that can range from loamy, sandy or even silty clay.

Black walnut and English walnut can technically grow in every state of the United States, but within each state are certain areas where walnut trees will grow optimally.

Overall, the five regions of the U.S. where black walnut and English walnut can grow include:

• West
• Southeast
• Midwest
• Southwest
• Northeast

In general, English walnuts can survive in colder conditions than black walnuts, while black walnuts can survive in warmer climates than English walnuts. Happy walnut planting!

References

Cambria, D., & Pierangeli, D. (2012, March). Application of a life cycle assessment to walnut tree (Juglans regia L.) high-quality wood production: a case study in southern Italy. Journal of Cleaner Production, 23(1), 37-46.

Fulton, A., & Buchner, R. (2006, February 23). The Effect of Water Stress on Walnut Tree Growth, Productivity, And Economics. UC Farm Advisors, 1-15.

Tang, H., Ren, Z., & Krczal, G. (2000). Improvement of English walnut somatic embryo germination and conversion by desiccation treatments and plantlet development by lower medium salts. In Vitro Cellular & Developmental Biology – Plant, 36, 47-50.

Von Kiparski, G. R., Lee, L. S., & Gillespie, A. R. (2007, May 01). Occurrence and Fate of the Phytotoxin Juglone in Alley Soils under Black Walnut Trees. Journal of Environmental Quality, 36(3), 709-717.

Walnut trees are rather distinctive because of their large, baseball-sized green fruit. Inside those fruits are some of the most delicious nuts: walnuts! But just how often do walnut trees produce walnuts?

Walnut trees will bear fruit once per year. However, the amount will vary each year. Occasionally, walnuts will not produce any fruits during the growing season because of stressors such as drought, pests, or lack of nutrients. Walnut trees bear walnuts around 7 years of age.

There are many trees in the walnut family, each with its unique characteristics. Let’s check them out and talk about how often you can expect walnuts on your tree!

Which Walnut Trees Produce Walnuts?

Walnut trees are found throughout the world in temperate and warm climates. There are a variety of different species, but only certain types are available in the US.

The four most common trees that produce walnuts in North America include:

• Black walnut
• English walnut
• Butternut (white walnut)
• Heartnut

All walnut trees produce walnuts, but the number of nuts produced will depend on the weather and the available nutrients. 

Walnuts are cold-sensitive according to Utah State University. They don’t like super cold springs or early frosts in fall. One exception is the heartnut tree, which is native to Japan and is cold-hardy.

Their sensitivity to cold means that walnut trees may bear less fruit when the area they grow has late frosts in the spring or early frosts in the fall before the tree has time to harden off.

Black walnut and English walnut are the two most popular trees used for nut production. California is the country’s number 1 walnut producer. Oregon and Utah are two more states that produce walnuts, among others.

The walnut that most of us recognize and eat is from the English walnut tree. Black walnuts are still grown and used for nut production, but the shells are more difficult to crack and the taste is far bolder than that of an English walnut.

These commercially important trees are grown in orchards similar to how apples or other fruit trees are grown. Orchards keep the trees smaller than their natural height of over 100 feet. 

Orchard walnut trees are chosen selectively based on their trait to yield high amounts of nuts and resist pests and disease. 

Those who have a walnut tree in their backyard may observe low walnut yields, which could be because of the genetic makeup of the tree or the conditions under which it grows

Or your walnut tree might drive you crazy because it produces too many walnuts!

How Often Do Walnut Trees Bear Fruits/Walnuts?

If it seems like we are interchanging the word fruit and nut in this article, it’s because we are! Nuts are considered the fruit of the walnut tree.

If you don’t believe me, the U.S Forest Service even defines nuts like walnuts as fruits as they have a single dry seed, hard shell, and protective husk.

Nut-bearing trees produce nuts enclosed in some kind of protective husk, which is then protected by another outside layer. This last layer is leathery or waxy.

In the case of the walnut tree, the outer layer can be green or a washed-out yellow-green color. The inner ‘nut meat’, as it’s called, is the actual walnut. 

Walnuts are an important food source for wild critters as well. Squirrels especially like to nab walnuts and hide them away for winter.

So, how often can you expect your backyard walnut to bear these delicious and healthy fruits, nuts, whatever you want to call them?

Walnut trees will produce a crop of walnuts every year starting around age 7 to 15, depending on the species. High yields occur about every 2 to 3 years, with low yields in between.

The best nut yields will not occur until the tree is over 20 years of age.

If you want to learn more about how many walnuts you can expect on your tree, check out our piece, How Many Walnuts Grow On A Tree? Full Walnut Timeline.

Why Isn’t My Walnut Tree Producing Any Walnuts?

Have a walnut tree, but it’s not producing any nuts? What gives? 

If your walnut tree does not seem to produce any nuts or the yields have been consistently low, there are several reasons this is happening.

Late Frost

We mentioned earlier walnut trees are not big fans of cold weather. They need plenty of time to prepare for winter by slowing production and growth when the days get shorter.

The same can be said for spring. Walnut trees may bloom too early in the spring and then the blooms are killed off by a late frost in April. In this case, the flowers and catkins needed for pollination will not bloom. Without pollination, the fruits will not develop.

Lack Of Nutrients

Nutrients are important for any tree to survive and thrive. Fertilizers are typically packed with the nutrients that trees need, such as phosphorus, nitrogen, and potassium, depending on the species.

Once a tree is established, it does not need any help to get the nutrients it needs because the roots of the tree can extrapolate the minerals from the soil.

However, some soils that are disturbed by humans will lack proper nutrients for walnut trees. Leaf litter is an important organic material that is degraded in the winter and absorbed into the soil, providing nutrients for the tree the next year.

In areas like HOA suburban neighborhoods or cities where leaf litter is required to be picked up, trees will suffer more because of it.

If a walnut tree cannot get the proper nutrients it needs, it cannot transport them to the stems and leaves, and the tree will struggle to produce fruits and new buds.

According to the University of Missouri Center for Agroforestry, the most important nutrients for a walnut tree are:

• Nitrogen
• Phosphorus
• Potassium
• Calcium
• Magnesium
• Iron
• Manganese
• Zinc
• Boron
• Copper

If your walnut tree is struggling to produce fruit and you notice some browning leaves or early leaf drop, your tree may need some fertilizer to help it out.

You can purchase something like Jobe’s Organics Tree Spikes for Fruit and Nuts. This product comes as a spike, which you hammer into the ground around your walnut tree’s dripline.

The spikes offer a constant, slow release of the required nutrients your walnut tree needs. It comes with a pack of 8, so you can surround your tree with the spikes, keeping your tree happy and healthy.

Some reviews mention dogs like to dig up the spikes, so check your work every few days to make sure Fido is not getting into trouble!

Pests

There are hundreds of different pest insects to all kinds of different trees. Beetles, caterpillars, ants, flies, and mealybugs can all affect trees, among others.

The walnut husk fly is the most common pest of walnut trees. After emerging from the soil in July, adult husk flies will mate and lay eggs beneath the surface of the walnut husk. Once the eggs hatch, the maggots (gross) feed on the walnut husk for a few weeks.

Once they are rolly-polly from eating the husk, the maggots drop to the soil to pupate and start the entire process over.

The walnuts of your tree are still edible despite the flies and their maggots, but the nuts are often stained black and are unsightly. If you know maggots have touched the nut, would you want to eat it?

While pests may not cause your walnut tree to produce less fruit, they may cause the nuts to be uncollectable or useless.

There are a few ways you can control these pesky husk flies so they do not bother your walnut tree.

• Remove All Fallen Nuts: Picking up all the fallen nuts as soon as they fall can remove some of the larvae still on the nuts, reducing next year’s population.

• Use Landscape Fabric: Place landscape fabric like ECOgardener Premium 5oz Pro Garden Landscape Fabric beneath your walnut tree’s canopy. This prevents the maggots from reaching the soil, stopping the cycle for next year’s population of husk flies.

• Use Traps Paired With Spray: You can use sticky fly traps to gauge when the adult husk flies are emerging from the soil. Once the traps fill up with the flies, it’s time to use a spray to keep them off your walnut tree.

A sticky trap like Trappify’s Hanging Fly Stick Trap will work great at attracting the husk flies and trapping them. It comes with a hook so you can hang it from any branch of your walnut tree or on a nearby shepherd’s hook.

As soon as you notice husk flies lurking about, use a spray like Monterey’s Garden Insect Spray with Spinosad Concentrate. This is a concentrated product, so it will need to be mixed with water. 

Always follow the directions on the label for the proper mixing levels.

It is okay to use this product directly on your tree as it is approved for organic gardening. Pairing the trap with the spray is a great idea if the first two suggestions do not seem to work for your husk fly problem.

Alternating Pollination Periods

Another reason your walnut tree is not producing as many nuts is because of the lack of pollination.

Walnut trees are monoecious, meaning both the male and female parts are present on the tree. This typically means that the tree can self-pollinate.

However, with the walnut tree, self-pollination does not always happen. The male may disperse its pollen when the female flowers are not receptive. If the trees cannot pollinate, fruits will not form.

How Many Years Will A Walnut Tree Produce Walnuts For?

Whether you enjoy gathering fallen walnuts or cannot stand them littering your yard, at some point your walnut tree will age and slow down.

In orchards, walnut trees only last for about 35 years, according to the University of California, Davis. In the wild, walnut trees can live for hundreds of years, but on average they last around 200 years.

If your walnut tree is young, do not expect it to stop producing nuts soon. 

As all trees age, they slow their growth, and eventually, growth becomes minuscule. This is about when a tree reaches its maximum height. At this point, walnut trees will continue to produce fruits, but the yields will be much lower than when the tree was a strapping young adult.

The walnut tree will struggle to defy gravity to transport water and nutrients to the rest of the tree, which will limit flowering and therefore fruit production.

How To Make A Walnut Tree Not Produce Walnuts

The large fruits of a walnut tree can dent cars, thump noggins, and surprise the heck out of you if you’re walking beneath a tree while the fruit is falling.

Not to mention, walnut fruits will litter your lawn as they fall, creating a mess of green and blackened fruits and husks. Is there any way to stop this from happening?

If you are not interested in collecting the walnuts and would rather not litter your yard with them, there are a couple of things you can do.

Use Fertilizer

This may seem counterproductive. After all, doesn’t fertilizer help trees grow faster and provide more nutrients?

Well, that’s kind of the point. We want to flood the tree with nutrients to promote new growth.

The more energy the tree is putting into growing, the less energy it is putting into fruit production. Fertilizers rich in nitrogen should do the trick!

Clip New Walnut Blooms

This option is only viable while the tree is young. You can use a pruning tool to clip off new blossoms in the spring. 

This prevents the flowers from ever blooming, which means no pollination, which means no messy walnuts to clean up in the fall.

Cut Down Walnut Saplings

Squirrels help propagate walnut trees all over the place. They bury their nuts in the soil and then forget about them. These buried nuts then grow into new walnut trees.

As the saplings emerge, you’ll want to clip, cut, or saw them down. Having more than one black walnut tree in your yard increases the chance of wind pollinating, which will increase fruit yields. 

While the tree itself can self-pollinate, yields are smaller than if more walnut trees are around to help with pollination.

Black walnut trees may harm your garden as well. This might drive you to get rid of them on your property. To learn more, take a look at 20 Plants Not To Grow Under A Black Walnut Tree.

How Do I Know What Kind Of Walnut Tree Is In My Yard?

If there are tons of varieties of walnut trees, how are you supposed to know which walnut you have growing in your backyard?

Black walnuts are the most common walnut trees in the wild. Butternut trees will also grow in the wild but are not as common as black walnuts. English walnut trees are grown strictly in orchards and are not common to see in the wild.

If you’d like to learn more about the difference specifically between black walnut trees and other walnut varieties, take a look at our article: 8 Differences Between Black Walnut Trees and Walnut Trees.

Let’s check out some differences between these two trees so you know exactly which tree is littering your yard with fruits and nut husks!

Walnut Tree Height

Height at maturity is a big indicator. Black walnut trees will grow up to 100 feet, while a butternut tree’s maximum height is only 60 feet.

However, if your tree is not fully grown, it can be difficult to tell the difference between the two, as they have many similar characteristics.

Walnut Tree Fruit

Another way to tell the difference between black walnut and butternut trees is to check out the actual nuts once they fall off.

Black walnuts are round, while butternut walnuts thin out at the ends in a tear-drop. Sometimes they will have points at both ends, and sometimes one end is rounded while the other is more pointed.

Walnut Tree Bark

Just like height, the bark of your walnut tree may be difficult to distinguish when the tree is young. But if your tree is mature, the bark should appear different between the two.

Black walnut trees typically have heavily furrowed, dark brown bark. Butternut walnuts, or white walnuts, have smooth greyish white bark

That’s A Wrap!

As this article comes to a close, you should be packed to the gills with walnut knowledge! Who knew there was so much to know about walnut trees?

To recap, walnut trees will bear fruit once per year, ripening in the fall. High yields of walnuts happen every 2 to 3 years, with low production in between.

You can expect your walnut tree to continue producing nuts through its lifespan, but as the tree ages, fruit production will continually decrease. If you do not want the walnuts at all, there are a few steps you can take to lessen or eliminate walnut production.

References

Avanzato, D. (2010). TRADITIONAL AND MODERN USES OF WALNUT. Acta Hortic. 861, 89-96 DOI: 10.17660/ActaHortic.2010.861.11

Cannella, C. and Dernini, S. (2005). WALNUT: INSIGHTS AND NUTRITIONAL VALUE. Acta Hortic. 705, 547-550 DOI: 10.17660/ActaHortic.2005.705.80

Chudhary, Z., Khera, R. A., Hanif, M. A., Ayub, M. A., & Hamrouni, L. (2020). Chapter 49 – Walnut. Medicinal Plants of South Asia, 671-684.

Mamadjanov, D.K. (2005). WALNUT FRUIT FORESTS AND DIVERSITY OF WALNUT TREE (JUGLANS REGIA L.) IN KYRGYZSTAN. Acta Hortic. 705, 173-176 DOI: 10.17660/ActaHortic.2005.705.20

Molyneux, R. J., Mahoney, N., Kim, J. H., & Campbell, B. C. (2007, October 20). Mycotoxins in edible tree nuts. International Journal of Food Microbiology, 119(1-2), 72-78.

Today we’re talking about the differences between black walnut trees and walnut trees! Keep reading, we’ve got a list of differences between these two trees that you’ll want to know.

The walnut that we usually enjoy eating today is called the English walnut from the English walnut tree. However, there is a walnut tree found throughout North America that is the only wild nut tree in the United States, the black walnut tree. Black walnut trees are largely used for their wood.

Black walnuts are incredibly nutritious but are traditionally hard to harvest. Read on to learn about the wild black walnut tree as well as the protein-packed and valuable wood from the walnut tree!

Black Walnuts Are Wild, English Walnuts Come From Orchards

The black walnut, Juglans nigra, is a commonly found tree in the United States. They have huge husks similar to the size of tennis balls and are also of similar color.

The black walnut tree reaches a height of 75 feet and even is found to be heights of 150 feet. Historically, Native Americans and European settlers used black walnut trees due to their variety of uses. 

The black walnut can be consumed and the husks can be used for dyes because black walnuts have a slightly more bitter taste than English walnuts; they are used for flooring, gun stocks, and even furniture! The black walnut tree is the only wild nut tree in the United States. 

Black walnuts, similar to black cherry trees, are considered pioneer species since they easily grow in barren environments. Also contributing to their success as a wild nut tree, is the fact that they are allelopathic, meaning that they release chemicals into the ground from their roots, making the surrounding area uninhabitable for other trees.

The English walnut, Juglans regia, originated from Persia, modern-day Iran. The English walnut is harvested exclusively from orchards for a few reasons. Due to its highly palatable flavor, the English walnut is extensively used in desserts, baking, oils, and other food products.

The English walnut is significantly easier to open as compared to its counterpart, the black walnut, and is what we commonly find in stores when we go to buy walnuts. The English walnut, although commonly used for foodstuff, is also used in furniture, cabinetry, guitars, millwork, and construction.

Talk about a Jack of All Trades! Walnut wood is resistant to decay and warping, shrinks mildly, and is a hardwood that is easy to work with.

Black Walnut Hulls Stain

Black walnut trees are incredibly versatile, which is no wonder the black walnut has numerous historical uses.

Black walnuts contain juglone, which acts as a mordant for dyeing fibers. This allows permanent dyeing of materials without the use of other substances that would normally allow the dye to stick. 

Other walnut trees produce juglone but at a substantially lower amount than black walnut trees. The dye from black walnuts comes from the hulls, which encases the fruit or the nut. The dye is released by soaking and simmering black walnut hulls in water. 

The neon green tennis ball-sized black walnut hulls produce a tan to black colored dye on both plant and animal fibers, depending on how long the material is soaked in the dye. The dye is so potent that hulls can be saved and frozen to use for dyeing throughout the year, additionally, hulls stain skin, countertops, and sinks.

Black Walnuts Have The Highest Protein Content Of All Nuts

The black walnut contains the highest amount of protein found in any tree nut! Additionally, they have high levels of vitamin A, iron, fiber, and antioxidants. Walnuts are a great way to get protein, healthy fats, and essential vitamins.

Both English walnuts and black walnuts are powerhouses, packed full of antioxidants and polyunsaturated fats, which help to lower blood sugar, balance gut bacteria, reduce cholesterol, and help improve cardiovascular health.

Black walnuts have the highest level of protein of any nut and one cup of black walnuts has 32 grams of protein and 8 grams of fiber, although high in fat and calories. 

Black walnuts are full of vitamins and minerals such as vitamin E, folates, melatonin, iron, potassium, and magnesium. In comparison, English walnuts have 16 grams of protein, higher fat content, and 8 grams of fiber. In addition, walnuts are a great source of vitamin B6, manganese, copper, and folic acid. 

While walnuts may be high in fats, they contain high levels of healthy fats. All walnuts contain high levels of omega-6 fatty acids and omega-3 fatty acids. 

Black Walnuts Are The Only Wild Nut Tree

The black walnut tree grows throughout North America, from Canada to Florida. It grows exceptionally well in sandy loam soil or clay soil. Black walnut trees are widely used in construction, hardwood flooring, and even in desserts and for baking. 

Roughly 65% of wild harvests come from Missouri annually. Black walnuts are considered to be a pioneer species because they grow easily along roads, like a weed, and pop up in barren forest regions as a result of forest fires. Black walnut trees also grow easily in full sun and spread aggressively. 

Furthermore, the hulls and nuts provide food for surrounding animals. Animals then spread the walnut seeds through excretion, enabling them to spread fast. 

Black walnuts grow quickly and are allelopathic, meaning that they produce a biochemical called juglone that influences other plants. It inhibits the growth of plants competing with the black walnut by releasing the juglone into the environment. 

This biological phenomenon directly contributes to their spread across the Northeast of the United States as the only wild nut tree.

Kinda cool, but we have a black walnut tree on our property 🙂

You can check out our black walnut tree here.

English Walnuts Are Generally Grown For Food, Black Walnuts Are Generally Grown For Their Wood

Although black walnuts are highly nutritious and easy to find, they are not the main provider of walnuts that we consume. Generally, the walnuts we find in the grocery store are from English walnut trees. 

English walnuts have a much thinner and easily breakable shell or hull compared to the black walnut, allowing the fruit to be harvested more easily and as a whole.

Black walnut trees are typically grown more so for their wood, due to the nature of their hard-to-harvest fruit from hulls. Black walnut wood is used in furniture, gunstocks, oars, coffins, and flooring. The wood has a remarkably straight grain and is a beautiful dark color. 

Black walnut is extremely valuable due to its hardness and ease to work with, as well as resistance to insects and decay, and is on par with cedar and black locust. Black walnut trees also grow comparatively quicker than English walnut trees attributed to their use for timber.

Walnut trees, although generally known to chemically ward off other plants, can be companion planted with certain vegetables. Juglone is a toxin that excretes from walnut trees and can inhibit other plants from growing nearby. However, some plants are resistant to this. If you were about to give up on your black walnut tree, here are some vegetables that are resistant to juglone:

• Beans
• Beets
• Carrots
• Corn
• Melons
• Onions
• Parsnips
• Squashes 

Walnut trees are also traditionally known to have medicinal properties. The leaves have been used to treat conditions such as swelling, ulcers, and diarrhea.

English Walnuts Originated From Persia, Black Walnuts Are Native To North America

The black walnut is native to eastern North America. Black walnuts adapt easily to a variety of environments and are the first to grow in barren environments after fires, and alongside roads; making them what is known as a “pioneer species”. 

The English walnut tree, however, is said to have originated from Persia, modern-day Iran, and brought to Greece and the Roman empire. These were traditionally revered as royal gifts and known as foods of the Gods. 

They were said to have been sent to the King of Greece from the King of Persia, contributing to their spread throughout the world. It wasn’t until the mid-1700s that the English walnut was cultivated in the United States in California and was commercially planted in the mid-1800s.

Black Walnuts Have An Incredibly Tough Shell, English Walnuts Have A Thin, Soft Shell

If you have ever seen a black walnut up close and personal, you have probably almost broken your ankle on one of the tennis ball-sized husks. I have done that more than once even though they are lime green! 

The shells of black walnuts are incredibly hard and would probably injure you if you got hit with one. Their shell is so hard that some sources say to drive over the hull with your car.

Although, if you’re not up for that, the best way to harvest the nuts is on a hard surface with a hammer. Yeah, they are that hard! I know it is a common practice to step on the walnuts with shoes, but personally, that has never worked for me. 

Black walnut shells are commonly used in sandblasting, that’s how hard they are! They can be used to sandblast ships, smokestacks, and even jet engines!

English walnuts, on the other hand, have a much softer and thinner husk, which comes off much more easily than that of black walnuts. English walnuts occasionally have hard-to-remove hulls that stick tight against the seed, but compared to black walnut husk removal, the English walnut seems like a breeze! 

Once the shell has been removed from the English walnut, removing the nut inside is easy. The English walnut meat can also be harvested more easily as a whole. For black walnuts, harvesting them whole is almost impossible. This in part, is probably why the English walnut has been grown in orchards, harvested, and sold in grocery stores. 

Black Walnut Trees Grow 75-100 Feet Tall, English Walnut Trees Grow 40-60 Feet Tall

English walnut trees take significantly longer to mature and produce a large crop of nuts, than their counterpart, the black walnut. Nuts can begin to be produced around 4-6 years but generally take 20 years before a crop can be harvested. 

The black walnut is significantly larger than the English walnut tree. It grows to a height of 75-100 feet tall and can have a spread of 75-100 feet wide. Currently, the Black Walnut of Virginia tree made the National Register of Champion Trees in 2019 at a whopping circumference of 246 inches, 104 feet tall, and a crown spread of 56 feet!

Although the English walnut tree typically ranges from 40-60 feet tall, Giant Ogden in Utah ranks as the largest English walnut tree in the state. It was planted more than 100 years ago and is 85 feet tall and has a trunk circumference of 223 inches!

That’s A Wrap!

That’s all we have on the differences between black walnut trees and walnut trees. Walnuts are chock full of essential vitamins, protein, and minerals, moreover, they have a diverse range of uses.

To recap, here are the 8 differences between black walnut and walnut trees:

• Black walnuts are wild, English walnuts are from orchards
• Walnut wood is resistant to decay, warping, shrinking, and is incredibly hard
• Black walnut hulls stain
• Black walnuts have numerous health benefits and the highest protein content of all nuts
• Walnuts are jam-packed with vitamins, minerals, and an abundance of healthy fats
• Black walnuts are the only wild nut tree
• English walnuts are generally grown for food, black walnuts are generally grown for their wood
• You can grow juglone resistant vegetables near walnut trees including beans, beets, carrots, corn, melons, onions, parsnips, and squashes
• English walnuts originated from Persia, Black walnuts are native to North America
• Black walnuts have an incredibly tough shell, English walnuts have a thin, soft shell
• Black walnut trees grow 75-100 ft tall, English walnut trees grow 40-60 ft tall

Walnuts are serious nutritional powerhouses with loads of vitamins and minerals. The black walnut and English walnut, although similar, have vastly different tree sizes and uses. 

Additionally, all types of walnuts are used for their fruit as well as for their wood. Contrary to popular belief, there are juglone-resistant plants, including a handful of vegetables. Walnut trees are incredibly versatile. 

Although the black walnut tree has commonly been thought of as a nightmare, these health-packed nut trees might have just become my new favorite! Maybe yours too?

References:

Browne, Greg T., et al. “Resistance to Phytophthora and graft compatibility with Persian walnut among selections of Chinese wingnut.” HortScience 46.3 (2011): 371-376.

Querné, Aurélie, et al. “Effects of walnut trees on biological nitrogen fixation and yield of intercropped alfalfa in a Mediterranean agroforestry system.” European Journal of Agronomy 84 (2017): 35-46.

Rugman-Jones, Paul F., et al. “Phylogeography of the walnut twig beetle, Pityophthorus juglandis, the vector of thousand cankers disease in North American walnut trees.” PLoS One 10.2 (2015): e0118264.

Schlesinger, Richard C., and Robert D. Williams. “Growth response of black walnut to interplanted trees.” Forest Ecology and Management 9.3 (1984): 235-243.

Tooley, Paul W., and Kerrie L. Kyde. “Susceptibility of some eastern forest species to Phytophthora ramorum.” Plant Disease 91.4 (2007): 435-438.

Walnut trees, most commonly English and black walnuts in the United States, are used most often for their nut production and sometimes timber. But how many walnuts grow on a tree each year?

On average, a mature walnut tree produces 50 to 80 pounds of unshelled nuts every year. Many species of walnut tree will begin producing at 7 to 8 years old but take until the 15-year mark to mature fully. Some walnut trees produce more heavily every other year as well.

We’ll be discussing how to plant and properly care for a walnut tree. This includes pointers to help your walnut tree grow! Alongside this, we will cover the full timeline of a walnut tree’s life.

Walnut Growing Season And Conditions

Walnuts have a growing season ranging from 140 to 150 days, beginning in late April or early May.

Most walnut trees require the temperature to stay above 27 to 29 ℉ while in the early stages of ripening. Walnut harvesting season is from mid-September through November.

You can tell they are ready for harvest when the hulls turn green, split, and start to fall naturally from the tree. 

Despite this, there are some hardier species like the Carpathian English Walnut. These are better suited for harsh winter climates. The Common English walnut, butternut, heartnut, and black walnuts are more acceptable in milder and warmer climates. Be sure to choose the right species for your local climate! 

How Long Does It Take To Grow A Walnut Tree? A Full Timeline 

Say you find walnuts nearby. What’s next? How much time and care will go into growing it? How soon can you expect to harvest walnuts of your own? 

While walnut trees are not the most complex to care for, they do require more attention than some others, like oak trees. However, walnut trees give back many times over in nut production what they require in care. 

Starting from the top, or more appropriately the nut, let’s go through the full timeline of growing a walnut tree! 

If you’d like to learn more about walnuts, read our post: 8 Differences Between Black Walnut Trees and Walnut Trees.

Day 1: Finding Viable Walnuts To Plant

The first step to planting your own walnut tree is finding viable walnuts. Identify a local species of walnut tree and wait for the perfect moment.

Collect your walnuts in the fall during their harvest season! Some walnuts, like black walnuts, need to be hulled and washed directly after collection. When doing so, wear protective gloves. Some walnut trees have toxic oils on their leaves and in their sap. 

You might find something like the Large Nut Wizard useful for gathering numerous walnuts. You’ll need quite a few to get started, so collect as many as you see fit, within reason of course. It will also come in handy once your tree bears nuts for you to harvest in the future!

While you are washing your walnuts, discard any that may float. If walnuts float, they are underdeveloped or poorly filled. Poorly filled walnuts will not germinate properly, so keep an eye out for the ones that sink! They’ll be perfect to move on to the next step. 

From the walnuts that sunk during washing, cut open a small sample. If they are full of solid, white meat, then they are viable. Non-viable walnuts will be beige and give off an unpleasant smell. Use this information to generate a percentage of viable nuts out of what has been collected. 

If a large percentage of the harvested walnuts are viable, you will need fewer nuts per plot or container. Now we’re ready to move to the next stage of preparation, stratifying.

Day 1-120: Stratifying Your Walnuts

Stratification is an important, but not completely necessary, step to your walnut tree journey. It can be done in one of two ways. 

Place your walnuts in a container filled with a mixture of damp sterile sand and peat moss. This aids in germination and will help ensure it is uniform later on. Place the walnuts in your mixture at 2-3inch layers and keep refrigerated for 90 to 120 days.

An example of moss would be Hoffman Canadian Sphagnum Peat Moss. It increases the amount of moisture your mixture will hold, as well as the time it will stay moist. When you’re keeping your walnuts moist for up to 4 months, dampening them less often definitely comes in handy!

While stratifying, you can use containers like coffee cans, plastic storage bags, buckets, and similar closed spaces. As long as they fit in your refrigerator, you can use them. 

During this time, the sand and peat moss mixture must remain moist and cool.

The optimal temperature range for stratifying walnuts is 33 to 40 ℉. In terms of moisture, the sand and peat should be damp to the touch, but not soaked. Too much moisture may lead to molding. 

This process can be done naturally as well, though it is less controlled. By planting in a similar mixture in the fall and leaving them throughout the winter, the walnuts will experience the same dormancy.

With this method, you risk a large freeze halting germination completely.  

After stratification is complete, you can finally move on to planting your walnuts! 

Day 1-120: Planting Walnuts In The Spring

According to the University of Missouri, there are multiple ways to plant your walnuts. These include planting in plots, creating a nursery, and planting in containers. 

If you are going to plant in a plot, also known as in place, there is a bit of extra preparation. A seedbed for planting is the first step. It should be in an area that gets full sun.

You should also weed the area and keep it weed-free throughout the time it takes your walnuts to sprout. 

After tilling and preparing the soil, dig 2 inch deep planting plots and place three to five stratified nuts per plot. Depending on the species, plots should be 20 to 80 feet apart.

The soil should be moist and kept moist for sprouting. Space out the walnuts in each plot as well as you will only keep the strongest ones in the future. 

A nursery is another viable method for planting multiple walnut trees. Unlike planting in a plot, these will require transplanting later on. A seedbed is the first step in this method as well, though it will look slightly different. 

Like before, till the soil and dig 2 inch deep holes for your walnuts. With this method, they should be 2 feet apart in rows that are a minimum of 4 feet apart.

Keep your nursery weeded and well-watered throughout sprouting and while growing your seedlings. You will transplant the seedlings the following year, which we will cover further down.

The last method, growing trees in containers, allows for the close monitoring of the nursery, with earlier and simpler transplanting later on.

Choose open bottom containers, the preferred type, or planters with sufficient drainage. The open bottom containers allow for air pruning, which helps prevent taproot circling. If you are using open bottom containers, place them on a wire bench to allow this air pruning to occur. 

The potting soil you choose needs to allow free movement of water throughout the entire container. Mix in a slow-release fertilizer that will allow your walnut tree to get the proper nutrients for approximately seven to nine months. 

Plant only one stratified nut per container and water daily. Container-grown trees require very careful attention and monitoring.

However, container-grown seedlings can be transplanted in the fall instead of the following spring. They can be held in containers over the winter, but be sure to keep the roots protected from freezing temperatures and insulated.

After the trees go dormant, cover them with an insulating cover or hay mulch. 

Day 1- Year 1: Fertilization And Transplanting Of Your Seedlings 

Keep an eye out for germination in four to five weeks. Your walnuts will begin sprouting and will require more attention. 

Around mid-June in all cases aside from container planting, fertilize your seedlings with a slow-release fertilizer. Each plot should be fertilized in the first method, and fertilization occurs per row in the nursery method. 

After fertilization, seedlings from the plot and nursery methods require watering once conditions become dry. Continue to water your container trees daily until transplanting. Any seedling area will need to be kept weed-free during this time as well. 

For your container planted trees, the transplanting season starts three weeks to a month before the first killing frost and can continue into mid-November. If you keep them warm and covered as we discussed before, they can be held until the spring. 

Weed and prepare the new planting location and start digging your walnut seedling a new home! The hole needs to be twice as wide as the root ball, and 16 to 18 inches deep, and spaced properly.

You should attempt to preserve as many roots as possible during this process. Space the holes according to the walnut species, though 30 to 50 feet is usually safe for planting at home. 

Throughout this first year, monitor all of your nursery and plot seedlings to decide which ones you will keep.

The strongest growing tree at each plot, as well as your strongest nursery contenders, needs to be selected out of the bunch. Any other seedlings can be cut off below the root collar and disposed of. 

You will transfer your nursery seedlings at the end of this section of the timeline. Once your seedlings are a year old, around March, the seedlings you choose to transplant need prepped.

To transplant, you will need to dig 16 to 18 inches deep around each seedling, preserving as many fibrous roots as you can.

The transplant process from here is the same as with the container-grown seedlings. Walnut seedlings will benefit from a layer of mulch 2 to 3 inches thick, kept away from the bark to prevent rotting.

Years 1-5: Growing Walnut Saplings

Once you have transplanted your saplings, the work gets lighter but does not end. Keeping the area weeded and properly watered is most important at this stage. 

For the first 2 years, your saplings will need your help to get water regularly. You should water your seedlings as soon as the ground has dried completely around them. Deep watering, or watering down into the soil, will also be necessary periodically. 

Deep watering can be done less frequently, around one to three times a month at the hottest point of the year, after the 2 to 3-year mark. The irrigation should occur about 2 feet deep around your tree. Walnut trees are not considered drought-hardy and benefit from this irrigation. 

Pruning will also help your sapling stay healthy and grow through the early stages. This should be done sometime between the late summer and late fall. If walnut trees are pruned during the late winter or spring, it may cause bleeding or excessive sap flow. 

When pruning, remove any damaged branches to prevent further spread. Thinning out crowded areas allows for more sunlight and air to reach the tree as well. 

Years 5-15: From Seedling To Fruit Bearing Walnut Tree

Year 5 is the earliest your tree will begin producing nuts, though most start year 7 or 8. By the time you reach year 15, your tree should be in full production, providing the 50 to 80 pounds of nuts mentioned earlier. 

When it comes to harvesting the fruits of your labor, you will know it’s time when the nuts begin to fall themselves. After you notice this, you can encourage the ripe nuts by gently shaking the limbs by hand or with something long and sturdy. 

At this point, the nut collector you used to collect your initial walnut will come in handy again! After shaking, roll the cage along the ground, gathering the nuts. The quality of walnuts depreciates quite quickly, so be sure to collect them often.

Nuts lose quality faster inside their husks. If the husks remain after harvest, remove them manually. Easier to remove husks can be hand-peeled or rolled against a hard surface until they come free. For those that are harder to remove, dampen and store in an airtight container for 1 to 3 days. 

All nuts need to be washed after their husks are removed to get rid of any remaining material. Walnut husks can stain your skin, so wear gloves!

Walnuts can then be dried in one of three ways between 95 and 105 ℉: 

• Place on baking sheets outdoors: Make sure your trays somewhere they will receive plenty of sunlight (a southern wall preferably) and wait for 3 to 4 days.
• Dry on baking sheets indoors: They can be dried similarly indoors with low humidity. 
• Place in an onion sack: Hang indoors, but be sure to shake the bag daily to rotate the nuts. 

You can tell your walnuts are properly dried when the kernels and the packing material are brittle and break easily. 

Once dry, you can store walnuts for 3 months to 2 plus years depending on the storage method. Always keep them stored in a cool, dry place.

At room temperature, walnuts will keep for 3 to 6 months. 

To keep your walnuts good for even longer, store them at even lower temperatures. Below 32 ℉, they last up to a year. If you store them below 0℉, walnuts may stay good for 2 or more years. 

Years 15-50: Maturing Walnut Trees For Timber

Other than just nuts, walnut trees are often used for their timber. Walnut wood is very hard and sought after for projects such as furniture building. 

Your tree can fit the criteria for timber sale anywhere from 30 to 80 years after planting. The longer it is allowed to grow taller, the more it will be worth. Also, the straighter your walnut tree is, it is more likely to meet the proper standards for sale. 

According to the Missouri Department of Conservation, there are two types of walnut wood quality. Veneer or lumber grade are the categories your tree might fall into.

The specifications for both are quite different, but veneer trees are much rarer, raising demand for them. 

Consult a forester to assist you in identifying the value of your trees.

Your Results Walnut Disappoint! 

Terrible puns aside, that’s all the information we have for now! Hopefully, you have a decent concept of what and how long growing a walnut tree takes.

With time and a bit of dedication, you’ll have walnuts to spare in the future!

You may decide to keep your walnut tree for many generations to enjoy. You might also decide to continue to plant and teach them how to sell their own trees in the future. Either way, your beautiful trees will provide for you and yours for many years to come.

References:

Balandier, P., Lacointe, A., Le Roux, X., Sinoquet, H., Cruiziat, P., & Le Dizès, S. (2000). SIMWAL: a structural-functional model simulating single walnut tree growth in response to climate and pruning. Annals of Forest Science, 57(5), 571-585.

University, U. S. (n.d.). Walnuts in the Home Orchard. Extension.usu.edu. Retrieved November 4, 2021, from https://extension.usu.edu/yardandgarden/research/walnuts-in-the-home-orchard

Pecan and Black Walnut in Agroforestry Practices. (n.d.). Retrieved November 4, 2021, fromhttps://extension.missouri.edu/media/wysiwyg/Extensiondata/Pub/pdf/agguides/agroforestry/af1003.pdf

Le Dizès, S., Cruiziat, P., Lacointe, A., Sinoquet, H., Le Roux, X., Balandier, P., & Jacquet, P. (1997). A model for simulating structure-function relationships in walnut tree growth processes.

Selling Walnut Timber. (n.d.). Missouri Department of Conservation. https://mdc.mo.gov/magazines/conservationist/2013-02/selling-walnut-timber