Black Walnuts: Fall Treat or Scourge?

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Black walnuts ripen in late summer and early fall. Though hard nuts to crack, the both sweet and savory bold flavor is worth the effort.
Photo by JamesDeMers on Pixabay

Late summer and fall bring a treat — or scourge — to many people’s backyards, depending on your point of view. Black walnuts are one of the most valuable and fully utilized natural forest trees in the United States…or one of the most nuisance trees around. Folks either love them or hate them, there usually isn’t any middle ground.

Although they are found in 32 states, they are most abundant in Missouri (some of us beg to differ on this fact), where they are the state tree nut (not to be confused with state tree, which is the flowering dogwood). They can be planted but are not grown in orchards, instead growing wild in yards, fields and forests.

They make great shade trees since their average height is 50 feet tall and some have even been reported to reaching 100 feet. They grow just as wide which provides lots of shade. Since their lifespan is 150 years, the trees are destined to be around for quite some time. In autumn, their leaves turn bright yellow which is in stark contrast to their black trunks.

The black walnut is a very versatile tree. Its fruit is used in both sweet and savory dishes, its wood is prized for furniture and gun stocks and the husks are used to make dyes. Its shells are the hardest of any tree nut in the world.

They have quite the repertoire. Not to be confused with the English walnut, black walnut shells have been used to clean the Statue of Liberty and the United States Navy have used them to clean its ships and submarines. They are also used as filler in dynamite.

The Nuts

Here is where the controversy comes into play: They start falling and cluttering up a yard in late summer. Since they don’t all fall at once, it is a never-ending task. If you don’t like the nutmeats, this can seem like an un-ending chore, especially when mature trees can produce between 66 and 350 pounds of nuts per tree per year. However, if you like their rich, bold taste, then it becomes a labor of love.

These unique, all natural sustainable nuts have the highest level of protein of any nut and they are still all picked by hand. Early settlers added them to soups and stews and ground them into meal for baking. The sweet, earthy nutmeats are also a tasty snack when eaten raw. Their hard shells provide a perfect package for storing the nuts over winter.

Harvesting Black Walnuts

They should be collected as soon after they fall as possible to avoid molding or letting squirrels and other creatures beat you to them. There are basically only two ways to do this, either pick them up by hand or use a nut collector which is a tool that you roll over the ground and it collects them.

Removing the hulls is the hard part, literally. Some folks hit them with a hammer, some strew them in their driveways and run over them with vehicles and some use nutcrackers. There used to be an elderly gentleman from my area that would collect all the walnuts he could and then would sit and crack them while watching basketball games on TV all winter.

Whichever method you use, it works best if you strike the shell at a ninety-degree angle to the seam of the shell then use pliers to chip away at the rest. Remember to wear gloves since they will stain your hands.

After you have successfully cracked the nuts and gotten the nutmeats out, they need to be dried for a couple weeks. Either lay the meats on a screen or drying rack or put them in a mesh bag so they can get good air flow. They can be stored un-shelled for up to a year, preferably in the freezer.

Lumber from Black Walnuts

The easily worked, close-grained wood of the black walnut tree is highly prized by furniture and cabinet makers. The attractive color and exceptional durability of the logs makes them in such high demand for veneer that walnut rustlers would harvest trees in the dead of night, sometimes even by helicopter.

Early settlers found that the rich brown heartwood was very resistant to decay. Thus, they used them for just about everything, including fence posts, poles and shingles.

Photo by Lois Hoffman

Growing Black Walnut Trees

Black walnut trees are surprisingly easy to grow. If grown with other trees in close proximity, they tend to grow straight and tall. Thus, those grown in a forest tend to have long, straight trunks, the exact characteristics that make them ideal lumber logs. However, if you are planting them with this intention, keep in mind that it is a two-generation process for them to get large enough to make veneer logs.

If they are planted in the open, they branch out more. To reach maturity and start bearing nuts takes 8 to 10 years. Unlike other trees, black walnuts are prone to a unique reproductive pattern known as alternate or biennial bearing. It’s a natural phenomenon that prevents trees from over-extending their resources. This is the reason that one year a tree will produce a heavy crop while other years there will be a light or no crop of walnuts.

The Dark Side of Black Walnuts

Roots of black walnuts can extend up to 50 feet from the base of the tree and exude a natural herbicide called juglone. This is also present in the leaves and fruit and is the reason why many plants will not grow under or around walnut trees. This reserves water and nutrients for the tree itself by limiting its competition.

This is also why tomatoes, potatoes, pears, berries and many other fruits, vegetables and landscape plants are stunted or killed if planted under the trees or in close proximity of the tree’s dripline.

Quirky Black Walnut Facts

Nitrogen can limit fruiting. If your love/hate relationship with these trees borders on the hate side, you can intercept and reduce the amount of nuts a tree produces by applying a nitrogen fertilizer to the soil around the tree in early spring and late summer. Water well to make sure the nitrogen soaks into the root zone so it is absorbed. According to Washington State University, extra nitrogen causes a flush of vegetation growth while limiting fruit production.

Attracts lighting strikes? Many folks refrain from planting black walnut trees near their homes or other buildings because they tend to draw lightning strikes. Although we have all heard that “oaks draw the strokes,” black walnuts rate right up with them. All trees attract lightning because they are tall, filled with moisture, and provide good conductivity. Lightning frequently selects large, deep-rooted tree species, and walnut trees fit the bill.

For sale! Walnuts can be “one shell of a business.” There are approximately 215 buying stations across the country that will buy these hard gems, however they only deal in large quantities. If you have only a couple trees, you can still sell them to local buyers — and don’t forget that the nutmeats are not the only valuable part in demand. Some companies also buy the hulls to use in different processes.

Love them or hate them, black walnut trees are scattered throughout the country and are unique in their own right.

Photo by Hans Braxmeier on Pixabay

Lois Hoffman is a freelance writer and photographer covering rural living with more than 20 years of experience, contributing to Successful Farming, Country, and Farm & Ranch Living. She lives on a 37-acre hobby farm in Michigan. Read all of Lois’ GRIT posts here.

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  • Updated on Oct 3, 2021
  • Originally Published on Sep 27, 2021
Tagged with: Lois Hoffman, nut, nut trees, tree, walnut
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