The black walnut tree (Juglans nigra) grows throughout the United States. Its native range extends through the eastern and central states. Highly valued as a major timber tree, the black walnut commands high prices for its wood per board foot according to the University of Minnesota. The tree produces wood that is famous for its strength, beautiful coloring and excellent machining ability. The tree's nuts are popular for baking, candy making and retail sale. The black walnut tree makes an excellent shade specimen with pleasing yellow fall colors.
Plant walnut trees in an area that is well-draining. The tree will not tolerate wet roots. The sun prefers full sunlight. An area with ample wind protection is ideal. The ideal soil conditions should have a pH higher then 7.
Prune the walnut tree during its dormant period in the winter or early spring. Remove dead or damaged branches. Prune trees limbs that are less then 1 or 2 inches in diameter to allow air flow and sunlight to reach the tree.
Remove all weeds and turf grass around the black walnut tree. A 3 foot diameter is ideal. Care should always be taken when cultivating around the black walnut tree using a hoe or other machine because the trees roots are shallow and easily damaged. The trunk of the tree is also easily damaged. Any damage that occurs can allow infections to enter the tree's system.
Apply 3 to 4 inches of mulch such as peat moss, bark chips or leaf debris around the tree. Mulch will help lessen weed growth and also help the soil maintain moisture.
Water the black walnut tree regularly. Keep the soil moist but not water-logged.
Fertilize the black walnut tree in early June using 1 cup of 10-10-10 fertilizer for every year of the trees life. Sprinkle the fertilizer around the tree's base. Do not allow the fertilizer to touch the trees trunk. Water thoroughly.