The Eastern black walnut grows best in coves and well-drained bottoms, as found in the Appalachians and the Midwest. It does well particularly well along streams and on the lower portion of slopes facing northeast. It is commonly found on limestone soils. It does not do well on wet bottom land and on sandy, dry ridges and slopes. Link: https://www.na.fs.fed.us/spfo/pubs/silvics_manual/volume_2/juglans/nigra.htm
Origin, history, and uses:
American settlers discovered the eastern black walnut in forest throughout the “New World” using it as fence posts, shingles, sills, and poles because of its resistance to decay. It was heavily harvested, with “walnut rustlers” taking trees in the middle of the night and sometimes even using helicopters to ferret them away. The wood was traditionally used to make solid furniture and gunstocks but in recent years has been mostly used for veneers as the supply has diminished. The nuts are used for desserts - baked goods and ice cream - while the shells are ground and used in a variety of products.
Flowering and leafing occur around the same time, in about mid-April in the South and can appear anywhere from this time until early June in the northern part of its range.
Walnut is monoecious with male flowers developing from auxillary buds on the previous year's outer nodes, while female flowers occurring in short terminal spikes. Female flowers develop before male flowers. They usually do not self-fertilize but, if not pollinated by nearby trees, will set out self-fertilized trees. After pollination, the tree undergoes fertilization, husk development, shell development, and finally seed development.
Large edible nuts ripen in the fall, usually September or October, and drop after the leaves fall in the winter.