Black walnut (Juglans nigra) is one of the most valuable native hardwood trees. It has dark straight grained wood used for furniture and gunstocks. If trunks are straight and no foreign material like nails are inside it likely would command the highest price per board foot of any tree on your property.
Black walnuts range over most of the eastern states from New York southward to Georgia and west to eastern Texas. It is quite common in our region. Leaves are alternate on the stem and each leaf contains many elongated blades. If you cut a stem lengthwise you will notice a dark center that has air pockets or chambers in it. This is called a chambered pith and is a primary identifying characteristic of black walnut and its cousin the butternut (Juglans cineria), whose range is a little more northern. The only butternuts (white walnuts) found in North Carolina are in the western mountains.
Our native species has rich flavored nuts high in linolenic acid, an Omega 3 compound. They also contain a compound called ellagic acid, an antioxidant which fights free radicals. This compound also helps discourage cancer cells.
Nuts can be harvested once leaves begin to yellow and fall off. If the squirrel population is high you will compete for them. Nuts are covered by a thick light green husk, making them look a little like lemons or small tennis balls. This husk must be removed or the bitter tannins in it along with mold residue can taint the nuts. This task can be accomplished in several ways. Commercial hullers are available but I use one of two methods, depending upon how many I have.
The first technique is to roll them under my foot on a concrete driveway until the husk loosens and comes off. This works well if I have only a half bushel or so. Large quantities can be hulled by spreading them out on a gravel driveway and driving over them for a few days. You might damage a few, but you’ll get satisfactory results. Once hulled the nuts can be dried and stored for a long time.
You can also crack them and seal the meats in freezer bags. You can even lightly roast and seal them in heated canning jars with lids. Now the cracking part can be a trick. Shells are thick and you have to smack them firmly with a hammer. The problem is that if you hit them too hard you will crush the delicate meats. With a little practice it becomes easy.
Black walnut shells are very hard and used to polish metals. Shells are ground and used in sand blasting equipment. They can also be used in paints, cosmetics and explosives.
Walnut husks and inner bark can be used for many things, especially dyes. Many cultures have used them medicinally, but any product that high in tannins would give me dosage concerns. I’ve used bark and hulls to boil traps and tan hides. I have some home recipes but will have to share them some other time.
Ted Manzer teaches agriculture at Northeastern High School.