Q.Walnut tree dropping nuts
Why would my walnut tree shed its nuts early? They are falling all over the yard, but not mature.
If there's not enough water or nutrients getting to the tree, this could cause them to drop. The tree can't sustain all the walnuts so it sheds some, so that it can focus its energy on its roots and continued new growth. If you have squirrels and chipmunks, don't forget they knock off walnuts as they jump between branches. Some years you'll have a smaller crop of walnuts, that's normal. I have a gigantic black walnut tree in my yard, and some years I've had hardly any (or almost all of them fell early), other years I've had tons. If the branches and leaves are healthy with no signs of pest or disease, it shouldn't be anything to worry about. These articles may help you determine whether there's something actually wrong with the tree or it's simply thinning itself a bit so that it stays healthy:
https://www.gardeningknowhow.com/plant-problems/disease/anthracnose-disease.htm
https://www.gardeningknowhow.com/edible/nut-trees/walnut/how-to-prune-walnut-trees.htm
https://www.gardeningknowhow.com/edible/nut-trees/walnut/planting-walnut-trees.htm