Prepare the edamame seed bed by turning the soil over with the spade and smashing any large clods. Rake the bed smooth.
Plant the edamame seeds 1 inch deep and 3 inches apart, in rows 24 inches apart.
Water the bed carefully so that you don't wash the edamame seeds away. Wait four days and if there has been no rain, water the top 3 inches of soil. Edamame seeds have a tendency to rot if they receive too much water.
Spread a 3-inch layer of organic mulch on the soil around the edamame plants when they reach 4 inches tall. Don't allow the mulch to touch the plants.
Water the edamame plants when there has been no rain for four to five days. Moisten the top 6 inches of soil.
Fertilize the edamame when the plant produces flowers. Use a 10-10-10 fertilizer according to label instructions.
Harvest the edamame 85 days after planting or when the edamame pods are full.