8 Differences Between Black Walnut Trees and Walnut Trees

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.