To add a black walnut tree to your yard, it is best to plant the seeds yourself. Although this can be a lengthy process, it is simple and can help teach the basics of planting other trees that you can add to your garden in the future, like fruit trees. When planted properly, black walnuts can be harvested the following fall season.
Find black walnuts throughout the fall as they fall from mature black walnut trees. Gather the largest and heaviest black walnuts, which will produce stronger seedlings.
Place the black walnuts in a container of luke warm water in order to soften the husk. Once it feels soft in your hands, peel away the husk. If you see nuts that float, throw them away as they are not seeds that will germinate.
Fill a plastic bag with peat moss sprinkled in water. Use a safety pin to poke several holes throughout the plastic for proper ventilation, and add the walnuts. Put this bag in the refrigerator for at least three months in order to mimic the winter season that seeds go through.
Make sure to keep the peat moss damp, and if you see any mold growing remove that peat moss patch or walnut immediately to discard.
Plant the black walnuts in spring in a full sun location after they have germinated. Dig a hole about two inches deep, insert two nuts in each hole, then cover with loose soil and water generously until you see sprouts in the ground. Plant the walnuts at least 10 feet apart.