Loosen the ground to a depth of 6 inches with a pickax and shovel. Remove rocks, weeds and grass from the site.
Spread a 2-inch layer of manure or other organic soil amendment over the seedbed. Incorporate the matter 6 inches deep with a shovel. Rake the area to make a smooth bed.
Dig a furrow with a hoe or by dragging the tip of your shovel's handle. Make the trench twice as deep as the Japanese persimmon seeds are wide. Separate multiple rows by 3 feet.
Sow the persimmon seeds 1 foot apart. Fill the furrows with topsoil.
Lay a soaker hose by the seeds, and irrigate the soil to a depth of 3 to 4 inches. Keep the seedbed moist to promote germination. Let the seedlings develop an entire growing season before using them as rootstock.