This photo is of black walnuts forming in early spring. The nuts grow in pairs and have a green outer coating. They'll continue to grow until they're about the size of a small plum or golf ball. But don't let the size fool you. The green outer coating is about a half inch thick and when it comes off, there's a hard shell underneath. The size of the black walnut without the coating is about the size of an English walnut.
The leaves on black walnut trees are one of the earliest to drop in the fall, leaving the nuts easy to spot. Once you identify a black walnut tree, you can check occasionally to see when the nuts are beginning to fall (they don't all fall at once).
If you leave black walnuts on the ground, their green coating begins to turn brown. Be careful picking up walnuts at this stage because this brown coating will stain your hands.
The walnuts in this photo have fallen and are just beginning to turn yellowish brown and then dark brown.
If you leave the nuts on the ground even longer, the brown coating begins to dry and won't be as soft and messy. However, the longer you leave them, squirrels may take them away or falling leaves will cover them so you can't find them again.
Whenever I go walking in the woods or where I know black walnut trees are, I always carry a bag or bucket and pick them up, even if they still have the green outer coating on them. I don't take chances that they'll be there when I come back.
If black walnut trees are near a road, cars often run over the nuts and break off the coating. Then you only have to pick up the nut itself. Unless they've completely dried out, you'll want to wear gloves so you won't stain your hands brown.
You can also remove the outer coating by putting the nuts in your driveway and driving over them; your tires will only break open the outer coating, not the actual nut shell. Don't use your driveway if it is made of concrete, though, because the brown walnut coating will stain it. And don't leave the nuts in your driveway if you have squirrels in the area. A friend left her nuts in the driveway overnight and by morning they were all gone! She could see squirrels in the trees eating them.
If you don't use your driveway, you can remove the outer coating by putting the nuts in a bucket or trash can and the coating will come off on its own once it dries out. Shuffle the nuts around now and then for air circulation. You could also spread them out on some newspaper in a screened-in porch or in your garage, again, shuffling them around now and then to let air get to all parts of the nuts.
Once the outer coating is removed, you'll need a hammer to crack them. Black walnut shells are the hardest shells of any nut tree. Once you crack the shells in half, you can put them in a bowl and use a nut pick to get the nut meats out at your leisure. If you let them sit open for a day or so, the nut meat will dry slightly and be easier to pick out.
This seems like a lot of trouble to get black walnuts, but they have a wonderful taste and I love getting free food!
If you don't have black walnut trees growing in your area, you might find them in some grocery stores, Farmers' Markets or health food stores. You can also order black walnuts online.
Because of their strong taste, black walnuts are not usually eaten as a snack, but are used in baked goods and candies. And of course, walnuts are a healthy food. They contain copper, manganese, magnesium and phosphorus. 14 nut halves have around 185 calories.