Bev, black walnut trees, like all plants, grow according to
conditions. Heartwood has many black walnuts; two happy neighbors pick
the nuts, one to sell them. I've never counted, but I suspect there
are twenty to thirty trees within five hundred feet of the house.
I have written in years past of a dozen black walnuts between the
house and the back woods edge that the squirrels planted and I
cultivated by simply not mowing them. Those trees are now about 25
years old and most of them are ten to twelve inches in diameter. For
the best furniture wood I prefer a slow-growing tree with tight grain.
These are candidates but I will refrain from cutting them as long as
possible.
If I were planting black walnuts I would plant them near a stream or
at least in a low area likely to have greater soil moisture. Most of
the trees at Heartwood are within a hundred feet of the stream or at
an elevation that means their tap roots are down into the side seepage
from the stream. Many trees are at the stream bank. The twelve above
are an exception and there are many other young ones planted the same
way. None are more than about thirty feet in elevation above the
stream level.
That is not to say that they won't grow in drier soil. They will, but
growth will be slower. Great furniture wood but slow wood production,
contraindicated for those of us in geezerhood as planters should add
thirty or forty years to their age.