Walnut grows best on moisture retaining soils such as sandy loam, loam, or silt loam textured soils but descent growth is often possible on silty clay loam soils. Walnut is common on limestone soils and grows exceptionally well on deep loams, loess soils, and fertile alluvial deposits. Agricultural soils that do not have a fragipan are also good black walnut soils. Greatest size is often reached along streams and on the lower portion of north or east facing slopes. Black walnut is intolerant of shade.
Young walnuts develops a large taproot and planted seedlings typically survive well.
The most commonly utilized reforestation nursery stock in Wisconsin is the 1-0 age class. The minimum number of first order lateral roots, greater than 1 mm in diameter, that an acceptable black walnut seedling should have is seven to nine. A seedling with greater than ten first order lateral roots is the best. Prolific stump sprouting will occur after cutting or fire on young black walnut trees. Direct seeding of black walnut has become a fashionable alternative to planting seedlings.