Juglans nigra English or Persian walnut, but thrives best in the warmer regions of fertile, lowland soils with high water tables, although it will also grow in drier soils, but much more slowly. Some soils preferred by black walnut include Alfisol and Entisol soil types. Walnut grows best on sandy loam, loam, or silt loam type soils but will also grow well on silty clay loam soils. It prefers these soils because they hold large quantities of water which the tree draws from during dry periods. Visually, black walnut is similar to the butternut ("Juglans cinerea") in leaf shape, and the range
Castanea sativa the plant can’t pollinate itself, making cross-pollination necessary. Some cultivars only produce one large nut per cupule, while others produce up to three nuts. The nut itself is composed of two skins: an external, shiny brown part, and an internal skin adhering to the fruit. Inside, there is an edible, creamy-white part developed from the cotyledon. The tree requires a mild climate and adequate moisture for good growth and a good nut harvest. Its year-growth (but not the rest of the tree) is sensitive to late spring and early autumn frosts, and is intolerant of lime. Under forest conditions, it