Black walnut (Juglans nigra) is native to North America and grows best in USDA hardiness zones 5 through 9A. This massive tree can mature to heights ranging from 60 to 70 feet (or more) with equally large spreads. Black walnut trees provide bushels of nuts full of nutrients, which you and the local wildlife can enjoy. According to the University of Minnesota, the planted walnut trees will begin producing nuts about 10 years after planting. Growing black walnut trees from seeds requires specific steps to ensure the seeds germinate.
Gather a number of seeds from the ground that dropped from a healthy walnut tree in the fall. Collect three to five black walnut seeds for each tree you want.
Place the nuts in a bucket of water for 24 hours; discard any black walnut seeds that float to the surface. Remove the husks by hand, or use a manual corn sheller.
Place the black walnut seeds in a plastic bag with enough moist sand to cover the nuts. Keep the sealed bag in a refrigerator with temperatures from 33 to 40 degrees F for three months. This is known as cold stratification, which is required for the black walnut seeds to germinate.
Clear the area for starting the black walnut seed of all foliage and debris in the spring. Dig a hole 2 inches deep and place three to five seeds in it. Cover the seeds with soil, and drench with water.
Water (as needed) to retain moist soil for the seeds to germinate into seedlings, and keep the planting area clear of weeds. Thin to one black walnut tree per planting site, if more than one seedling emerges. Select the healthiest looking tree during the first growing season, and cut back the others or plant in another location.