Black Walnut – Juglans nigra - Growing to over 70 feet, it is one of the most highly valued of North American hardwoods for timber. The Black Walnut has compound leaves and produces large, rich, flavorful nuts. Walnut prefers moist, rich soils, but will tolerate a wide range of soils. For best nut production, space 30 feet apart to develop a full, well-branched top. It should start producing nuts in 8-10 years. For timber use, space 8-10 feet apart.