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Red oak, white oak, which oak? Oak trees may all seem the same, but there are differences between them that are worth knowing of. Their growth rate, maximum size, bark and leaf color, and adaptability are some things to consider when planting an oak. 

In truth, white oak trees have grey bark that tends to be divided into small, vertical blocks on the tree, while red oak trees have dark red/grey/brown bark with a scaly texture. White oaks live up to 600 years and grow 18in annually, while red oaks live up to 500 years and grow 24in annually.

Truthfully, oak trees are quite durable, they are beautiful, and they can grow to last incredibly long. When it comes down to it, personal preference is a big player in choosing a tree, and we want to give you the right keys to do so.

What is the Lifespan of a Red Oak vs. White Oak?

There’s no question that red and white oaks have significant differences, but what exactly does that mean? Why does it matter?

For one, the lifespan of these two species can say a lot about longevity, their prime, and what to expect from each species.

White oaks as individual plants live for around five hundred to six hundred years. 

Lake Forest College research shows that red oaks, while similar in lifespan, do have a timeline that is cut a bit shorter than that of their white oak counterparts. Red oaks live about three hundred to five hundred years. 

So, we can see that the lower end of the typical lifespan of a white oak corresponds to the higher end of that of the red oak species. 

While let’s face it, that many hundreds of years are still almost longer than we may be able to comprehend, there is a good deal of variety within what that looks like between red and white oaks.

If you’re interested in learning how long oak trees live, you can view our guide and data of the full lifespan for each common oak tree here.

How Quickly Does An Oak Tree Grow?

Okay, now let’s talk about annual growth. White oaks grow incredibly slow at a rate of about 12 to 24 inches per year, which is relatively slow in relation to other trees of a similar caliber. 

Red oaks are pretty similar in this regard. Thanks to research from the Nebraska Forest Service, we see that red oak trees grow at a rate of about 18 to 24 inches per year. On average, this happens just a little more quickly than the typical white oak.

Physical Characteristics of Red & White Oak Trees

One of the most identifiable traits of difference between white oak trees and red oak trees is, naturally, their physical traits. Most commonly, this includes their various bark, leaf, and color differences.

If you’re interested, you can read our guide with the pros and cons of the best oak trees to plant here.

Bark Color

Bark color provides the most noticeable difference between red and white oak trees and is KEY to identifying the difference between each.

Red Oak Tree Bark Color

When trees are still young and trunks are thin, the bark is a smooth light grey. The winter sun causes this light color to be quite reflective, and the bark is surprisingly smooth before age has a chance to change its design. This can sometimes be seen on large branches of a mature tree. 

The bark of a red oak tree has a dark color that can only be described as red/grey/brown and has a scaly texture with thin, rounded ridges. Twigs end in a cluster of buds, and the red oak ends in reddish-brown twigs that display light-colored buds. 

As the bark ages, ridges develop and leave the trunk a mix of shiny grey with dark fissures coming through. On old trees, the bark deepens further to be a dark brown shade. In very aged trees, the very bottom portion of the trunk sports fissures that are deeper and ridges that are no longer the flat, even texture of a middle-aged tree. In old trees, there is a more pronounced texture and darker colors that range from dark grey to black. 

White Oak Tree Bark Color

The bark of a white oak tree is grey and tends to be divided into small, vertical blocks thanks to shallow fissures that run the length of the trunk. These thin, irregular flakes vary from light to a deeper, more ashen grey color.

Twigs are grey to purple in color, with buds that have blunt points. This is a bit unlike those of the red oak, which are a bit softer with more muted edges and coloring. 

Leaf Shape and Color

Below, we’re going to break down the leaf shape and color for red oak trees and the major differences for each. If you’re interested in learning the difference between oak and maple trees overall, you can read our piece on the major leaf and bark differences of oak and maple trees here.

Red Oak Tree Leaf Characteristics

These moderately shiny leaves have a wide variety of colors throughout the seasons; in the summer, they range from light to deep, dark green, and then shift to gold or crimson as the summer creeps on.

The leaf of a red oak tree is smooth, almost shiny. As deciduous trees, they have some irregular bristle-tipped teeth. They, on average, are about 4 to 10 inches long and 3 to 6 inches wide.

In the fall months, the leaves of a red oak continue to deepen to either a vibrant orange or an even deeper crimson. In the fall, these leaves can be bright red, maroon, crimson, golden-yellow, yellow-brown, or a mix of color even darker but just as stunning.

White Oak Tree Leaf Characteristics

White oaks have leaves that range from 5 to 9 inches long, while their width is smaller at 2 to 4 inches. Instead of more jagged, bristled points, they have blunt-ended ones that vary in size and shape based on the location and other trees around. 

The leaves are pretty thick and may not fall from the tree throughout the winter months, unlike those of the red oak. They will fall off eventually but do tend to last longer and provide a very picturesque contrast of bright white against a deep reddish-brown color.

Best Oak Tree Hardiness Zone

Do you ever find yourself wondering what exactly the best growing zone for an oak tree is? Have you wondered if that differs between red and white oaks? Well, we are certainly glad that you’ve kept reading this far because this one’s for you!

First, what on earth is a hardiness zone? 

The USDA defines different hardiness zones across the country, which can be found on a map here. Oak trees fall into the lower number range, which means that they are hardier trees. Okay… and?

Well, this means that these trees can do well in lower temperatures. 

The way that the USDA hardiness zones work is that each zone represents a range of 10 degrees Fahrenheit. The zones are then divided into letters A and B. They break down the 10-degree temperature range in half, the lower 5 degrees of the range and the higher. 

For example, zone 5 represents minimum temperatures in the range of -10 to -20 F. SO, subzone 5a would be referring to temperatures of -10 to -15 F, and subzone 5b refers to -15 to -20 F.

Does that make sense? If you aren’t quite there, we get it. This is a lot of letters and numbers to think about. So, we are going to explain a little more. 

A hardiness zone deals with the information on what types of plants can survive certain climate conditions, including the ability to survive in a given minimum temperature range. Queue our hardiness, or growing, zones! 

Hardiness is a measure of how well a plant will survive cold temperatures; the USDA zones cover the basics of these temperatures and predictions but, like most systems, cannot account for every factor. 

Precipitation, elevation, and freeze dates are some things that get overlooked in this system. It is, however, the standard, and so, therefore, we are explaining in those terms.

Now, does that make more sense? Let’s talk about what hardiness zones our oak trees fall into. Spoiler alert, this is one of the biggest similarities between these two species.

Also, if you’re thinking about planting an oak tree in your backyard, refer to the hardiness guide and check out our piece on planting oak trees in your backyard. 

Best Red Oak Tree Hardiness Zone

The Ohio Department of Natural Resources tells us that red oak trees thrive in partial to full sun and can be found in USDA hardiness zones 3 to 7. Generally, temperatures from 10 to -30 Fahrenheit are going to be survivable when it comes to red oak.

Red oak trees generally can survive up to USDA hardiness zone 8. Red oak trees can live anywhere from 300-500 years and can reach a full height of up to 140ft. Annually, red oak trees can grow up to 24in per year.

White Oak Tree Hardiness Zone

Now, here’s some interesting info for white oak trees.

White oaks range from zone 3b to zone 9b. Generally, varieties of white oak trees can survive in temperatures as low as 30 to -40 Fahrenheit. White oak trees can live anywhere from 500-600 years, grow up to 18in annually, and reach a full height of 80ft.

The reason for this range that we see for both types of oak is that some varieties of white oak may be a bit less hardy than others. Additionally, there are many factors to consider when looking at these zones. Temperature is not the only extenuating circumstance that could cause issues with a tree. 

Oak Tree Adaptability

Red and white oak trees are quite adaptable, but what kind of soil do they like, and where do they grow best? Well, let’s get to it!

Red Oak Tree Soil Preference

Red oaks can thrive in any soil. It doesn’t get much more adaptable than that, does it? 

Red oak trees prefer moist, deep soil that is rich and slightly acidic, but it can easily adapt to dry soils with neutral or even slightly alkaline pH.

White Oak Tree Soil Preference

One type of soil that white oaks do not thrive in is that which is shallow, too compact, or overused. 

White oak trees grow their very best in areas that have moist yet well-drained soils. However, like red oaks, they are adaptable to more adverse conditions thanks to their deep root system that allows them to tolerate drought as they mature. 

This species thrives in areas with slightly acidic, deep, rich soil where the sunlight beams and the water is not too abundant. 

How Tall Do Red and White Oak Trees Grow? 

Red and white oak trees can get pretty dang tall! Below, we’ve outlined a bit of a scenario for you regarding the natural growth of these oak trees.

Red Oak Tree 10 Year Height

At 10 years, the red oak tree is starting to get taller, so much so that it has now outgrown the people who planted it.

After 10 years, red oak trees are still quite young, but the trunk is getting a bit wider, and the height begins to make it look like a substantial tree. Red oak trees will be 15 to 20 feet tall at 10 years after first being planted.

White Oak Tree 10 Year Height

The white oak begins its first portion of life a bit more gently; following the red oak closely, a white oak tree will be 10 to 15 feet tall after 10 years of growth. Still taller than any person, it has not quite matured to the thickness or texture of a mature tree.

Red Oak Tree 25 Year Height

After 25 years, the red oak tree doubles and triples its size and will grow 35 to 40 feet tall. After 25 years, red oak trees will stand above a typical 2-story home and tower over people, younger trees, and most suburban architecture.

White Oak Tree 25 Year Height

At 25 years after being planted, a white oak tree will reach about 30 to 40 feet tall. At this point in its lifespan, the white oak tree is now a close competitor in the height category to the red oak.

Red Oak Tree 50 Year Height

50 years after the red oak tree was planted, it is about the height of a 4-story building, reaching 55 to 65 feet tall. 

White Oak Tree 50 Year Height

Did someone say a 4-story building after 50 years? Try a 5-story since the white oak is now generally taller for its age at 50 to 75 feet tall.

What is The Peak Height of an Oak Tree?

Overall, both red and oak trees have remarkable heights once fully grown. Here’s a peek at their full height below.

Red Oak Tree Peak Height

White oaks may have surpassed the red ones at the three 50 year mark, but let’s not forget that there are a ton of varieties of this species, and the northern red oak is one of them.

In many forests, red oak trees grow straight and tall, reaching a peak height of anywhere from 90 feet to an incredible 140 ft tall, while the trunk’s diameter reaches around 2 to 3 feet.

White Oak Tree Peak Height

The peak height of white oak can vary between the types of trees that fall under this title.

White oak trees often mature to something between 50 and 80 feet tall but are they are capable of growing upwards of 100 feet tall. 80 to 100 feet is a common range when we get to the ‘highest’ range of mature growth in this tree. In the individuals that grow to about 100 feet, the diameter of the trunk is going to be about 3 to 4 feet. 

These get HUGE.

That’s a Wrap!

Now that we know a little more about the major types of oak trees, how they grow, where they thrive, and what they can be expected to become in a few centuries, it’s clear that there is a lot to know about oaks.

Red and white oaks are similar trees but, at the end of the day, there are many differences that shape their identities as individual species. 

Keep in mind that white oaks tend to live a little longer, so if you’re worried about your descendants reaping the benefits of a specific tree you’ve planted, this might be the one for you. 

Red oaks, however, grow a little faster at 18-24 inches per year and can thrive in any type of soil. Now that is a combination of speed and adaptability that we can support.

Really, the choice is yours. What shade of bark or height do you want? What is a better option for your environment? The questions may be endless, but we hope this provides you with a good reference of what tree might just be the one for you.

Thanks for reading! Now, go plant a tree!!

References

Cook, E. R. (1985). A time series analysis approach to tree ring standardization (dendrochronology, forestry, dendroclimatology, autoregressive process). The University of Arizona.

LeBlanc, D. C., & Terrell, M. A. (2011). Comparison of growth–climate relationships between northern red oak and white oak across eastern North America. Canadian Journal of Forest Research, 41(10), 1936-1947.

Dougherty, P. M., Teskey, R. O., Phelps, J. E., & Hinckley, T. M. (1979). Net photosynthesis and early growth trends of a dominant white oak (Quercus alba L.). Plant Physiology, 64(6), 930-935.

Tardif, J. C., & Conciatori, F. (2006). Influence of climate on tree rings and vessel features in red oak and white oak growing near their northern distribution limit, southwestern Quebec, Canada. Canadian Journal of Forest Research, 36(9), 2317-2330.

Lightning striking your oak tree can be a rather interesting experience. When it happens and lightning actually does strike your oak tree, there are a few reasons why, and several things you can do in order to save your oak tree.

Oak trees are taller than most trees and are more likely to get struck by lightning due to their height. If your oak is struck by lightning, you will need to water, fertilize, and trim dead branches off the tree. Lightning damage on your oak tree will split the tree and cause burnt, black marks.

Stick around and we will answer all your pressing questions, including how to care for an oak tree that has been struck!

Can An Oak Tree Survive A Lightning Strike?

In short, yes, it is possible. An oak tree can survive a lightning strike, though it is going to take some time and care to get the tree back to healthy standing.

It is possible that your oak tree may not survive the level of damage caused by a direct lightning strike. It all depends on factors such as the intensity of the strike, the height of the tree, and how the lightning impacts the tree itself.

So, while oak trees can survive a lightning strike, it is not always a sure bet that they will. 

​​For that reason, we are also going to help you learn some best practices to follow as you work to maintain your oak tree’s vitality after a lightning strike. There are things you can do, from preparing and learning about lightning to understanding maintenance practices following a lightning strike. 

To understand an oak tree’s reaction to being struck by lightning, it is important to first understand what lightning is. 

Just Why Does Lightning Strike Oak Trees?

Essentially, lightning is a discharge of electricity. Such electricity also happens to be the cause of the thunder we also associate with thunderstorms. Oak trees are conductors of lightning because they offer a tall location close to the clouds and are full of moisture and sap that are better at conducting energy than the air and shorter plants nearby.

According to the UCAR Center for Science Education, just one stroke of lightning can heat the air nearby up to around 54,000 degrees Fahrenheit.

So, when this discharge of electricity, which is extremely hot, contacts a conductor such as an oak tree, it causes quite the commotion. Understandably so!

Not only does this lightning strike cause damage to the oak tree, but there is also a very audible reaction that occurs, which we are going to explain next.

What Does It Sound Like When Lightning Hits An Oak Tree?

The extreme temperatures generated by a bolt of lightning (let us not forget it is fifty-four thousand degrees Fahrenheit in the air), creates the sound that accompanies a lightning strike connecting with a oak tree, which is quite fierce.

The sound, explained by the Library of Congress to be a giant shock wave, sounds much like an extremely loud bolt.

The heat of the air causes the air itself to expand faster than the speed of sound, which results in hearing thunder very close to you, hence the loud noise that comes with lightning striking a nearby oak tree.

When lightning and thunder are close together, you know a storm is close. As the time increases between seeing a bolt of lightning and hearing a clap of thunder, the lightning is getting further away from you because the sound is taking longer to travel.

How Can You Tell If Lighting Struck A Oak Tree?

Sometimes, it is not even apparent your oak tree has been struck by lightning until it rapidly declines.

In this situation, the electric current of the lightning would have run through the inside of the oak tree, using the sap and internal moisture as a conductor. Internal damage caused by a lightning strike may not be noticeable on immediate inspection, but causes severe damage to the oak tree itself.

Lightning damage may also be seen in a range of forms, when visible from the outside. Lightning scars, which are black, singed-looking streaks down the oak tree, and loss of bark are two mild signs of this phenomenon.

Other external signs might be much more immediately noticeable, like the oak tree’s bark may be stripped off. Due to the way lightning strikes usually hit, this appears as spiral-shaped peels.

The North Carolina Cooperative Extension even details that a tree struck by lightning might burst into flames and explode. So, there is every level of damage possible- from internal and severe to external and less damaging to external and very severe.

Now that you know what to look for to see if your oak tree may have been (or was) struck by lightning, let’s talk about the odds of this happening.

What Are the Chances Of An Oak Tree Getting Struck by Lightning?

While trees, namely oaks, are common targets of lightning strikes, there is not much available research about how often exactly this occurs. 

With about 100 lightning strikes hitting earth each second, your oak tree could be a conductor of lightning one of these days.

A piece from the University of Georgia proves it is difficult to pin down an exact probability, but that a tree’s topographic location, height, and relative proximity to other structures all play a large role in assessing the risk of it getting struck.

It is not as common for oak trees to die from a lightning strike, so keep it in mind as you consider this. Your tree has a chance of getting struck, but there are many potential outcomes.

What To Do When Lightning Strikes Your Oak Tree

It’s all well and good to know about what is involved in preparing for a natural catastrophe like this, from checking your insurance to knowing what to look for when you suspect your oak tree has been struck, but the after is also crucial.

If your oak tree has been struck by lightning, there are many steps you can take to ensure that, when possible, the oak tree recovers and can thrive once again. Trees, especially oaks, are resilient and adaptable. It is important to learn how to help them as they learn to rely on themselves again.

Luckily, there are plenty of ways to help your tree as long as it is not damaged beyond repair. Helping with the upkeep that it would usually take care of by itself is going to be one of the biggest factors when working to support your tree’s life force regeneration.

Make Sure Your Oak Tree Gets Enough Water

One of the biggest detriments to an oak tree being able to begin its self-healing process is when the tree does not have enough water. Lightning striking the tree works to pull some of the moisture content from the tree itself, both in its roots and the sap that runs through the tree.

Some of the biggest damages to an oak tree comes in the form of losing liquid. This also happens to be one of the biggest reasons the tree is struck by lightning in the first place. 

As we have mentioned, oak trees are great conductors of lightning because of their height in relation to both the ground below them and to other structures such as buildings, cars, and people. 

The other reason is oak trees are such a great conductor of this electric current, and it all has to do with the same sap and water that are pulled from the oak tree during the strike. The moisture of these things draws lightning to the tree because it offers a path of least resistance. 

So, watch out for the water your oak tree is getting as it works to heal. Its biggest life force attracted the destruction in the first place, so your tree deserves all the rehydration it can get!

In addition to water, it’s very important that your oak tree gets proper sunlight as well.

Add Fertilizer To Your Oak Tree

If you are not sure what else to do as you attempt to keep your oak tree alive, add fertilizer into the mix.

Using fertilizer, along with the water you should already give your oak extra of, will help give your oak tree the nutrients needed to see fresh growth and revitalization. 

While the sap and moisture were stripped from the oak tree, so were other important nutrients.

Along with this, lightning strikes zap the energy out of a oak tree, which makes healing and eventual new growth a challenging feat when the tree is left alone to undertake it. 

Fertilizer offers very important nutrients that help the oak tree rebuild energy to continue its journey back to being a solid, viable organism.

This Miracle-Gro Garden Soil for Trees and Shrubs will help you stimulate your tree as you work to get it to the next spring and hope to see new growth. Not only is this product highly affordable, so you don’t have to stress about a struggling tree and costs, but it is also fortified with important minerals like phosphorus and iron.

To learn more about using fertilizer for your oak tree, check out our article: 3 Best Oak Tree Fertilizers (and How to Use Them).

Trim Dead Branches Off Your Oak Tree

Help your oak tree, both literally and figuratively, lose the dead weight by trimming any dead or dying branches. This is best done in the winter months because it is going to help catalyze new, healthy growth the oak tree desperately needs to remain viable. 

Most oak trees struck by lightning just need to make it to the next spring. Though it is not 100% guaranteed, any trees able to survive a lightning strike and then survive well enough to bloom new buds will make it in the long run.

You can also regularly trim your oak tree to stimulate growth and take care of any dead branches at any time, whether or not your tree is healing. By practicing this healthy maintenance, you take some stress off of your oak tree and allow it to flourish!

You’ll want to trim your oak trees sooner than later after a lightning strike, but it’s always best to trim oak trees during the winter or early spring. You can learn more about best oak trimming practices in our article: Best Time To Trim Oak Trees + Trimming Calendar And Tips.

Monitor Your Oak Tree

Along with the common tactics you will follow to ensure your oak tree can get back on the right track, just checking in is an important aspect of the road to recovery. 

By regularly observing your oak tree, you will have an idea of its progress, whether it is improving (we hope!) or declining (an unfortunate possibility).

Keep in mind not every tree is salvageable after a lightning strike. Do not blame yourself if your oak tree looks healthier and then slips back into decline. Such is the nature of… well, nature.

Most oak trees live to be 100-150 years old, so adding these tips can help that process, especially when the tree is struck by lightning. To learn more about specific types of oak tree general lifespan, read our article: How Long Do Live Oak Trees Live? Lifespan for All Common Types.

Wrapping It Up!

Now that we’ve learned a little more about what lightning is, how it can affect an oak tree, signs lightning struck your tree, and how to save it, all that’s left is to hope this does not happen to your tree.

If lightning has struck your oak tree, remember to evaluate the status of your tree’s wellbeing, give it extra water and fertilizer, and trim any dead branches as it embarks on its process of recovery.

When an oak tree is struck by lightning, it might die. This is always a possibility, but not nearly as probable as one might expect. If you take care of your oak tree following the strike, there is a good chance it will return to at least a version of its healthy self. 

Caring for an oak tree after a lightning strike takes work, but it will be clear to see whether your tree appears to be improving. If you do not see any improvement, it may be time to consider removal. If improvement continues, there is an increased chance your tree will make a recovery.

We hope this has helped you understand why lightning is attracted to trees, why and how it can be so detrimental, and what to look for if you think your tree has been targeted by this event.

If your oak tree has or may have been struck by lightning, remember to take the steps:

• Help the oak tree rehydrate as much as possible
• Fertilize the soil around your oak tree to stimulate regrowth 
• Trim any dead branches to allow the oak tree’s energy to be focused on growing new buds
• Check your oak tree once in a while to see how its progress is going

For now, thank you for reading!

References

Defandorf, F. M. (1955). A tree from the viewpoint of lightning. Journal of the Washington Academy of Sciences, 45(11), 333-339.

Gora, E. M., Bitzer, P. M., Burchfield, J. C., Schnitzer, S. A., & Yanoviak, S. P. (2017). Effects of lightning on trees: A predictive model based on in situ electrical resistivity. Ecology and Evolution, 7(20), 8523-8534.

Taylor, A. R. (1965). Diameter of lightning as indicated by tree scars. Journal of Geophysical Research, 70(22), 5693-5694

Today we’re talking about the best time to trim oak trees. Did you know trimming oak trees at certain times can be detrimental to your tree?

Oak trees respond best to trimming in the winter and early spring. Dates between October 1st and April 1st will usually provide optimal oak tree trimming conditions. This is because the tree, and potentially damaging fungi, are dormant, making your oak tree less susceptible to damage and disease.

Read on to learn about the best time and season to trim your oak trees. Did you know that there’s an optimal time to trim your oak trees? We’ve got you covered with a trimming calendar and the best zones for growing oak trees.

Here are our tips on general oak tree tips and the best time to trim oak trees.

The Best Time To Trim Oak Trees

Oak trees are commonly found throughout the world in temperate regions and even some tropical regions. Oaks belong to the genus Quercus, which consists of 400 species and are both deciduous and evergreen.

Oaks contain tannic acid, which helps in protection from fungal diseases and insect infestations. Although oak trees contain tannic acid, they are susceptible to a variety of diseases caused by both fungus and insects.

Oak trees are extremely susceptible to a handful of diseases, including sudden oak death and oak wilt. Both of which kill oak trees quickly. To avoid this, trim oak trees when the trees are dormant. 

If you are looking for a new tree trimmer, the Greenworks 40V 8-inch Cordless Pole Saw is a fantastic option! It has a 20-inch steel blade and an automatic oiler for peak efficiency!

The best time to trim oak trees is in the winter and early spring, preferably after October 1st and before April 1st. When your oak tree is dormant, the tree is not actively growing. Pruning trees during this time will limit and prevent the spread of fungal and insect infestations. 

Similarly, during winter, fungi and insects are dormant, so it is significantly less likely to spread diseases during this time..

Common Oak Tree Diseases That Happen From Trimming

You would think tannic acid would prevent oak trees from getting most diseases, or at least protect them. However, this is not the case. 

Some of the most significant and fatal diseases to oak trees include sudden oak death, Phytophthora ramorum, and oak wilt, Bretziella fagacearum. Both sudden oak death and oak wilt are diseases caused by mold and fungus, despite tannic acid being present. 

Sudden oak death, Phytophthora ramorum, is a water mold, or an oomycete, meaning it produces a motile zoospore. Motile zoospores can move towards and away from certain chemicals, i.e. food source chemicals, specifically in plant material. 

According to the USDA’s Animal and Plant Health Inspection Service, reports of sudden oak death began in 1995, and it is considered an invasive exotic species. Sudden oak death was first detected in San Francisco, California, and in Oregon, both of which have the exact climate this pathogen thrives in. 

This oak tree ailment can also affect over 75 different plant species, contributing to its spread. P. ramorum spreads through rain, contaminated irrigation or plants, and even contaminated soil. It creates calluses, also known as cankers, on the bark seeping black and red. 

Oak wilt, Bretziella fagacearum, is a fungal disease that rapidly kills thousands of oak trees every year. Unfortunately, oak wilt spreads to newly pruned trees in spring and summer. Fungal spores spread by attaching themselves to insects such as beetles that bore into the wood, and through firewood transportation by humans. 

Oak wilt can also be spread long distances via airborne spores and shorter distances via root systems beneath the ground. Oak wilt is a vascular wilt disease that prevents water from getting to the rest of the tree. 

As if this wasn’t bad enough, the fungus can overwinter on dead tissues on trees appearing in spring and summer, killing the tree within two months. 

Symptoms of oak will consist of exactly what the name states, wilting. Leaves may wilt and become discolored, resulting in defoliation, i.e., sudden leaf drop. There is currently no treatment for this disease, but arborists are working to conserve oak trees and limit the spread of this disease.

To learn more about all the common oak tree ailments, read our guide: What’s Wrong With My Oak Tree? 10 Most Common Oak Diseases.

Oak Tree Trimming Calendar By Name And Hardiness Zone

Species Of Trimmable Oak Trees And Where They Grow

White Oak Tree, Quercus alba

The white oak is a deciduous oak found in zones 3-9 and is native along the east coast of the United States, found as far north as Maine and south to Florida, and as far west as Minnesota and Texas.

We typically use white oak trees for timber and flooring. This oak species grows from 50 to 80 feet tall and even as tall as 100 feet!

You can learn more about white oak trees in our article: 32 Incredible Facts About White Oak Trees.

Willow Oak Tree, Quercus phellos

The willow oak is also a deciduous oak found in zones 5-9. This oak tolerates poorly draining acidic soils, and covers from East Coast to Midwestern United States. The willow oak typically grows anywhere from 40 to 75 feet, along the bank of swamps, streams, or canals.

Swamp White Oak Tree, Quercus bicolor

Swamp white oak trees are deciduous oak trees found throughout zones 3-8. It needs acidic wet soil but is also drought tolerant. 

Swamp white oak trees also grow at a slow to average rate and are native as far north as Southern Canada to the Midwestern United States. The swamp white oak gets as large as 50 to 60 feet and grows along the banks of swamps, lowlands, floodplains, lakes, and valleys.

Northern Pin Oak Tree, Quercus ellipsoidalis

The northern pin oak is a low-maintenance oak tree found in zones 4-7. This oak reaches a height of 50 to 70 feet and is drought tolerant, growing well in acidic and well-draining soils. 

This oak is a medium-sized deciduous oak with elliptical green leaves. This oak species lives from Canada to the Midwestern United States in sandy upland woods.

Scarlet Oak Tree, Quercus coccinea

The scarlet oak grows in zones 4-9 within the eastern part of the United States and is native to Missouri. It tolerates drought conditions and black walnuts and grows to 70 feet tall. 

Bur Oak Tree, Quercus macrocarpa

Bur oaks are native to Missouri and grow in zones 3-8. Although it prefers moist loamy soils, it can also withstand a variety of soil conditions. 

Bur oak trees grow in stream valleys like the Ozark in Missouri and bottomland soils.. This species of oak grows to a height of 60 to 80 feet tall and gets its name from the ring of mossy burrs found around the acorn.

Swamp Chestnut Tree, Quercus michauxii

Swamp chestnut oaks grow mainly in the southeast of the United States, and zones 5-9. This species is native to swampy areas, floodplains, and lowland wooded areas. 

Swamp chestnut oak trees reach heights of 40 to 60 feet and were traditionally used as a timber tree in the 1800s. The people of this time used it in flooring, wagons and tools, as well as baskets.

Pin Oak Tree, Quercus palustris

The pin oak is a medium-sized deciduous tree that grows in zones 4-8. It grows well in medium to wet acidic loamy soil, but can also tolerate poorly draining soils. 

However, pin oaks do not do well in alkaline soils. Pin oak trees grow anywhere from 50-70 feet and thrive in the lowlands of the Midwest. Some people commonly use pin oak trees as landscape trees and along streets.

English Oak Tree, Quercus robur

According to Nazareth College Plant Biology, English oaks are native to Western Asia and Europe, but were introduced to North America in the 1600s and came to use as timber in England. These trees grow anywhere from 40 to 70 feet and grow easily in a variety of soils, typically growing best in zones 5-8.

Red Oak Tree, Quercus rubra

The red oak, also called the northern red oak, is a deciduous oak tree found in zones 4-8 and is native to Missouri. This species of oak tolerates drought conditions, black walnuts, as well as air pollution. This is a fast-growing oak tree that reaches a height of 50 to 75 feet tall.

You can learn more about the red oak tree in our piece: 29 Incredible Facts About Red Oak Trees

Hardiness Zones Where Oak Trees Grow

You will find oak trees throughout North America and grow in almost every zone. They are most common in temperate regions like the United States, but also grow in Mexico, Asia, Europe, and even Africa.

According to the University of Idaho College of Natural Resources, various oak tree varieties grow throughout zones 2-9. With over 400 oak tree species, you can find oak trees in almost every environment. Oak trees thrive in a variety of soils from acidic to alkaline and from clayey to sandy.

In these hardiness zones, there are specific varieties that can grow in sub ranges of the parent range described above which we’ll discuss below! While trimming in these zones is best during the winter/early spring season, you can learn more about the best time to plant oak trees in our article: The Best Time to Plant an Oak Tree (And How to Do it)

Common Uses Of Full Grown Oak Trees

Oak trees are famous for their incredibly sturdy and long-lasting wood. For more commercial goods like fence posts, cabinets and floors, we use red oak. White oak is a durable wood that is used in furniture, to make barrels, canoes, and fence posts. Oak is great for construction and woodcarving because of its durability. 

Oak flooring comes from red and white oaks and is the most common wood flooring that allures people with its tight-knit grain you can stain in an array of colors. Oak flooring is probably the most wide-known use of oak that gives a timeless look to homes.

Some oak species have also been used in natural pharmaceuticals because of their anti-inflammatory and antibacterial properties from tannins found naturally in oak bark.

Historically, Native Americans used parts of the red oak and white oak to treat ailments and wounds. The oak tree is also sacred and used in ceremonies in certain Native American cultures. 

Acorns have been used to create flour, soups, and other types of foods. In traditional medicine, it has been used to treat hemorrhoids, diarrhea, ulcers, and wounds. Today, you can find oak bark sold over the counter as powders, teas, and liquid extracts.

Learn more about the uses of oak trees and what types are best for firewood here!

Best Time To Trim Oak Trees: In Conclusion

That’s all we have for today on the best time to trim oak trees, oak trimming calendar, and tips. If you have ever walked down a street with trees, gone for a hike, or hung out in a backyard, it’s a safe bet that you’ve seen an oak tree! Oak trees are widely beneficial to the ecosystem and provide us with a variety of things that are part of our everyday life.

To recap, here are the best times to trim oak trees, and a quick list of some tips: 

• The best time to trim or prune oak trees is in the winter when insects, fungus, and trees are dormant
• Oak trees are susceptible to devastating diseases like sudden oak death and oak wilt
• Oak trees grow in zones 2-9 throughout the world
• Oak trees can tolerate a variety of soils and environments
• We covered only 10 species of oak trees, but there are over 400 species of oak trees.
• We use oak trees for timber, construction, hardwood flooring, cabinets, and furniture. Traditional medicine and Native American cultures also find oak trees useful.

There you have it. Oak trees are incredibly durable yet simultaneously susceptible to rapidly spreading fungal diseases. They make up our deciduous forests and provide us with timber we use to build homes, furniture, and flooring. Next time you think about pruning your oak tree, refer to this article and keep in mind to only trim it in the winter!

If you’re finding that your oak tree has been affected by early trimming, read our guide: 10 Early Symptoms of a Dying Oak Tree: Prevention Guide

References:

Juice, S. M., Templer, P. H., Phillips, N. G., Ellison, A. M., & Pelini, S. L. (2016). Ecosystem warming increases sap flow rates of northern red oak trees. Ecosphere, 7(3), e01221.

Rose, Anita K., Cathryn H. Greenberg, and Todd M. Fearer. “Acorn production prediction models for five common oak species of the eastern United States.” The Journal of Wildlife Management 76.4 (2012): 750-758.

Taib, Mehdi et al. “Medicinal Uses, Phytochemistry, and Pharmacological Activities of Quercus Species.” Evidence-based complementary and alternative medicine : eCAM vol. 2020 1920683. 31 Jul. 2020, doi:10.1155/2020/1920683

Vettraino, A. M., et al. “Occurrence of Phytophthora species in oak stands in Italy and their association with declining oak trees.” Forest Pathology 32.1 (2002): 19-28.

Oak trees are one of the most popular trees in the world. Most commonly known for their height (often growing between 100 to 150 feet) and their adaptability, oaks are not immune to all threats. 

The most common oak tree diseases are oak leaf blister, armillaria root rot anthracnose, oak wilt, bacterial leaf scorch, powdery mildew, hypoxylon cankers, actinopelte leaf spot, mistletoe, and galls. In general, you can save your oak tree by nourishing your tree and removing affected branches.

So, what common issues should you look out for on your oak tree? We’re here to equip you with the best info to tackle the problem.  Keep on readin’ on!

What Kills Your Oak Trees?

In truth, oak trees, while some of the more disease resistant trees out there, can still be susceptible to a multitude of problems.

Oak tree saplings for instance, are more prone to problems than a full grown oak. However, full grown oaks can still develop problems during their lifespan.

Below is a chart of the most common oak tree diseases, how to fix them, and how severe the issue is.

If you’re interested, you can read our guide to the 10 early symptoms of a dying oak tree here.

Oak Leaf Blister

While most oak trees are susceptible to this fungus-based disease, it affects red and black oaks more severely. The level of severity is still low, regardless of the fact that some oaks are more susceptible than others. In cases of minor afflictions, little harm is caused to the oak tree and the symptoms may even be difficult to spot. 

Speaking of spots, this is what occurs when oak leaf blister is ranging toward the more severe end. The leaves begin to display patches that look like light green blisters, that turn brown and resemble a type of sap. These patches occur when fungus causes an overgrowth on affected leaves. 

Leaves with oak leaf blister grow faster than those without the tissue because the spores have more time to germinate during the winter freeze. The fungus typically lives in these spores before leaves have a chance to bud, and cause mayhem the moment that growth restarts in the spring.

Spores are spread, including those infected with fungus, in the fall months. This is a cyclical process that fungicides typically don’t have much control over. If you do try a fungicide, we suggest looking at this Natria’s Neem Oil Spray which works for both insects and fungi. You’ll want to apply this before the buds break in the spring. 

Armillaria Root Rot

Armillaria root rot is high severity issue for an oak tree, where everything from affected roots to entire trees need to be removed. 

You can expect to see a slow decline in the tree and, especially in wet weather, mushroom structures will appear around the base and roots of the tree. These mushrooms are a honey color that doesn’t look nearly as harmful as they really are- but now you know. This is not a fungus to be messed with.

Armillaria root rot can be most easily identified by the clusters of the mushrooms, but there are also other signs. Trees with this affliction will fight poor growth, have needles that are browning and leaves that are yellowing at incorrect times of the year, along with the possible overproduction of seeds and pinecones. 

Flat white sheets of fungal growth may also pair with thin black fungal strands that meet near the base of the trunk. The extra resin may be seeping from the tree, or the wood itself may be soft and stringy. 

The symptoms are endless- what we listed is just scratching the surface. This highly severe affliction not only will kill your oak tree, but it will make the process a long, messy one.  

So… how can you save your oak tree?

Reducing stress on your oak tree can help stop armillaria root rot. Mulching the soil that sits around the base of the tree to add nutrients and water trees, especially during a drought when stress is running high can help save your oak tree. 

Also, avoid wounding your trees. Wounds make trees more susceptible to getting armillaria root rot- so avoid that at all costs. Keep lawnmowers, darts, weed whackers, power tools, and other sharp tools away from your tree. 

Anthracnose

Anthracnose is not the most severe oak tree affliction on this list, but it should be a cause for concern. You’ll notice that your oak leaves may be turning a brown, rusty color along the veins along the foliage of your leaf. Typically, anthracnose is most prevalent during the fall to oak seasons.

If you want to avoid excessive pruning of affected branches, the worry that it will spread, or closely monitor your trees, it is time to nip this in the bud. 

If you are just planting your oak trees, space them far apart so that they have adequate access to fresh air and plenty of sunlight.

Additionally, when planting your oak tree, make sure you’re doing it at the correct time of year. You can read our guide on the best time to plant an oak tree here.

Chemical control is an option, but there are other ways to treat this issue if it does happen to arise in your tree. Pruning, sanitation, and monitoring are going to become the trifecta for you in your journey to manage this oak tree affliction.

Oak Wilt

This fungal affliction finds prominence in the Southeastern United States and may cause different symptoms in red oaks versus white oaks. 

Transmitted via fungal spores, or possibly one of the many varieties of bark beetles, oak wilt can cause quite the distruption to your trees.

Getting in to it, oak wilt affects red oak trees and white oak trees in very different ways.

In order to understand the sections below about oak wilt in red oak trees and white oak trees, you may want to read our guide on the key differences of red and white oak trees.

Red Oak Wilt

In red oaks, oak wilt manifests as a more severe and rapidly escalating issue.

Oak wilt in red oak trees is prevalent a few weeks from infection until symptoms appear, and the tree can perish in as little as a few months after that. Oak wilt in red oak trees is a much more severe process than their white oak counterparts will face.

At first, the leaves of your red oak tree will begin to wilt as a bronze color appears. This typically works its way from the edges of the tree, like small limbs and the ends of branches, before making it to the rest of the tree, such as the trunk. The leaves will begin to drop gradually as they simultaneously discolor. 

The oak wilt fungus continues to grow and it produces a sort of sticky layer underneath the bark of an infected tree that ranges from light grey to a tan color. With a strong, unpleasant smell, this layer may begin to split the bark as it expands and the tree perishes.

Most often, red oak trees never survive from oak wilt.

White Oak Wilt

White oaks display their resistance when it comes to oak wilt because they can live for years after the initial infection occurs.

Oak wilt in white oak trees can be managed in a variety of ways, from regulatory prevention to direct control using fungicides.

Bacterial Leaf Scorch 

Bacterial leaf scorch is an oak tree affliction that causes a halt in water, reddening, or yellowing of a tree that is followed by the browning of leaves. This loss of hardiness sees leaves drop eventually, leading up to passing of the tree as a whole. Symptoms most often appear after a summer drought, when water movement is already low.

Usually, bacterial leaf scorch is spread by tree-hopping insects. 

The severity is at a medium level due to the fact that regression is a gradual decline. This means that an oak tree could survive an additional 5 to 10 years after bacterial leaf scorch has been present until it needs to be removed. 

Bacterial leaf scorch is a less selective disease, affecting red, white, pin, bur, and shingle oaks, along with sycamore trees, maples, and other varieties.

To treat this bacterial leaf scorch, you will want to not only remove affected trees but replant resistant tree species in the same area to avoid another outbreak in the near future.

Look into insect control such as Organic Deet-Free Bug Repellent. Spray treatments are not currently available for the affliction itself, but controlling insects that may spread bacterial leaf scorch is a great first step. 

Powdery Mildew

In essence, powdery mildew is going to look like someone spilled some baby powder on the leaves of your tree, more than likely.

Powdery mildew is characterized by the way that many fungi combine to appear as a white dusting on the leaves of an infected tree. The Clemson Cooperative Extension tells us that this disease is not fatal, but can cause plant damage when the infection becomes severe. The severity level of powder mildew is medium.

White spots are only the first sign of powdery mildew on your oak tree, however. Other symptoms include leaf curling and discoloration, among other abnormal growths.

The powdery fungal growth is not even always visible on your oak. Though when it is, it tends to begin on the lower sections of the leaves. In severe cases, abnormal growth of the oak tree’s leaves will shift into yellow or brown colored leaves that are dried and may soon fall off the tree. 

Powdery mildew management can first be solved if you notice white spots or discoloration on just a few leaves. Simply removing these leaves may keep the fungus under control. 

If applicable, prune the dead branches as you pull off any dead leaves at the end of the growing season. This will help prevent powdery mildew from spanning into the next season, and the one after that, and so on.

Hypoxylon Canker

Hypoxylon cankers are common inhabitants of many varieties of oak trees, but only begin causing symptoms when trees are under stress. Much like canker sores that humans get- the bacteria and pathogens react to the stress the host organism is under and begin to take effect.

Thanks to Texas A&M’s Agrilife Extension, we know that symptoms of this hypoxylon canker manifest in a way that reflects that of most other declining trees.

From yellowing or browning leaves to reduced growth rates, thinning canopy and branches, and white stringy sap around the base, hypoxylon cankers aren’t great news. They also aren’t as severe as anthracnose or oak wilt in a red oak tree.

This is more of a medium concern when related to the other common oak tree threats we are discussing here today.

To control hypoxylon canker on your oak tree, eliminating stress (or reducing it at the very least) is going to be the best plan of action. Vertical mulching is a technique that ensures nutrients are properly added to the soil around a tree, enriching the roots and fortifying the tree against stress-fueled disease. 

Remedial pruning may also be your saving grace in this situation because you can remove the parts of the tree most affected by stress before the hypoxylon cankers spread to the rest of your oak tree. 

If all else fails, tree removal may be the way to go for you. This white-rot symptom quickly kills trees once it has spread, and may become a hazard to the vitality of other trees or even a safety hazard to people and pets. 

Actinopelte Leaf Spot 

Another affliction of medium severity, actinopelte is caused by fungus spores that last over the winter and are agitated by rain and wind in the spring months. Leaf spots will appear and may join together to form larger and more irregular blotches on the leaves. A dark, reddish-brown color makes green leaves look particularly sickly, and the more severely affected specimens will fall to the ground prematurely.

The management of actinopelte revolves around ideas of transplanting, minimizing stress, and properly fertilizing the area- all of which go hand-in-hand to create a better environment for an oak tree to flourish.

Mistletoe

Surely you’ve heard of mistletoe. I.E. ‘kiss me under…’, ‘ho ho the mistletoe’, you know, that sort of holiday tradition in the western world. Did you know that mistletoe is actually quite the parasitic pest? 

That’s right, mistletoe wraps itself around healthy oak trees and takes part of their water and minerals. The severity is low, however, because when it comes to food sources like chlorophyll, mistletoe handles that one on its own. Though mistletoe is not fully detrimental to trees, it still needs to be monitored.

To work on this problem, you’ll just need to cut off branches that are too tightly wound with this vine. Breaking off the tops of the mistletoe itself can also help.

Galls

These spots created by insects may simply make an oak tree look less appealing. However, they could also do enough harm to cause the oak tree to perish. Their severity level ranges from low to high for this reason: it is difficult to know what to expect when these little pests (gallmakers) join the party.

Galls are growths or swellings that are abnormal and most often caused by small wasps. One of the issues with these is that there is no way to cure galls on your oak tree fully. Once galls are on trees, they cannot be removed. 

Typically, galls cause aesthetic issues more than anything truly severe but in extreme cases, they can lead to the death of a tree. Often, the symptoms lie somewhere in the middle with severe leaf deformities or premature leaf drops.

Manage galls on your oak tree by simply removing and destroying fallen leaves that have been impacted by gall-makers. Prune or remove twigs that are sporting galls before holes have a chance to form, ensuring that this issue does not quickly spread. 

That’s All For Now!

Now that we know a little more about some common diseases and other threats to oak trees, it’s clear that these durable giants do have their limitations.

Ultimately, it helps to pick the right oak trees to plant from the get go. You can read our guide on the best oak trees to plant here.

If you want to keep your oak trees healthy and clear of threats, try using fungicides to prevent and eliminate these sorts of issues. You may also find that removing infected roots (and/or branches) works better than spraying, depending on what type of affliction your oak has, and at what stage you catch it.

We hope this helps you know what to expect, and have a better idea of how to tackle the problem!

References

Everitt, J. H., Escobar, D. E., Appel, D. N., Riggs, W. G., & Davis, M. R. (1999). Using airborne digital imagery for detecting oak wilt disease. Plant disease, 83(6), 502-505.

Juzwik, J., Appel, D. N., MacDonald, W. L., & Burks, S. (2011). Challenges and successes in managing oak wilt in the United States. Plant disease, 95(8), 888-900.