Black walnut trees are large 50 to 150-foot trees with large compound leaves. Each leaf is 12-24" long with13-23 leaflets. Black walnut leaves are often some of the first leaves falling in autumn. They give off a spicy odor when crushed.
Harvesting & Preparation
The great thing about black walnuts is that the processing will not take an entire day. You can collect the green nuts one day (or little by little). When you have a decent amount, lay them out on the driveway and drive over them a couple times to get the husk off. Then let them sit somewhere to dry. It would be wise to wear gloves and barn or work clothes when working with the husked nuts, as they tend to stain easily.
After the nuts are dry, they should be stored for a couple weeks to let the nutmeats dry out. When you have time (perhaps when the weather gets cold), you can crack open the nuts. I use a heavy cement block/brick and a hammer. You will probably want to do this in a back room, workshop, or somewhere you can easily sweep up shells. For black walnuts, it will take a good hard whack or two to get open. After that, I've found the nutmeats are comparatively easy and quick to extract.
Black walnuts are a fabulous "survival" food. Three and a half ounces of nutmeat provides 628 calories, 20.5 grams of protein, 59.3 grams of fat and almost 15 grams of carbs.
Though they don't give as much sap as a maple tree, black walnut trees can be tapped during early Spring, and the sap boiled down to make syrup.
Medicinal Value
Nutmeats are used internally to treat eczema. The green husks can be used to make a parasite tincture and are also used as a laxative. Wellness Mama says on her site that black walnut hulls are also good for easing digestive problems like flatulence and colic.
Other Uses
Black walnut wood is valuable in cabinetry and furniture making. The hulls have been used as a natural dye and ink. The nuts can be boiled to produce oil, and the inner bark makes good timber and cordage. I mentioned that walnut husks are known for killing internal parasites in people; it has also been used by many as a natural de-wormer for animals.
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White, Linda B. The Herbal Drugstore. United States of America: Rodale Inc., 2000. Print.
Tekiela, Stan. Trees of Michigan Field Guide. Cambridge, Minnesota: Adventure Publications, Inc., 2002. Print.
Brown, Tom Jr. Tom Brown's Field Guide to Wilderness Survival. New York: Berkley Books, 1983. Print.
Angier, Bradford. Field Guide to Wild Edible Plants. Harrisburd, Pennsylvania: Stackpole Books, 1974. Print