Walnut trees produce not only a delicious, nutritious nut but are used for their wood for fine furniture. These beautiful trees also provide shade in the landscape with their large, arching limbs.Walnuts (Juglans spp.) are attractive, nut-bearing landscape trees that offer shade in the summer and ornamental interest in the winter. Commonly planted varieties include the English walnut (Juglans regia) and the Northern California black walnut (Juglans hindsii). Also called the Persian walnut, the English variety typically winters well in U.S. Department of Agriculture plant hardiness zones 4 through 9, while the Northern California black walnut prefers the warmer winters offered in USDA zones 7 through 9. Giving your walnut proper care helps your tree grow healthy and strong.