Start indoors or direct sow?

Direct sow edamame because soybeans do not benefit much from transplanting and their roots are easily disturbed. In very short seasons, start seeds in biodegradable pots for only 2 to 3 weeks before planting out.

When to start Edamame seeds

Direct sow 1 to 2 weeks after the last spring frost, once soil is at least 60 to 65°F. For a staggered harvest, sow another small block 2 to 3 weeks later.

How to sow the seeds

Sow seeds 1 to 1 1/2 inches deep in well-drained, moderately fertile soil. Space seeds about 2 to 4 inches apart in rows, then thin to roughly 4 to 6 inches apart if plants are crowded.

Germination

Edamame usually germinates in 7 to 14 days in soil around 65 to 85°F. Keep the soil evenly moist until emergence, but do not let it remain saturated.

Seedling care

Give plants full sun and water consistently during flowering and pod filling. Thin for good airflow, keep weeds down early, and avoid frequent light watering that leaves the soil surface constantly wet.

Transplanting & hardening off

Direct sown, so no transplanting is needed. If started in biodegradable pots, harden off for several days and transplant after frost danger has passed without breaking up the root ball.

Tips

Use fresh seed and protect emerging seedlings from birds if they are a problem. Edamame needs a longer season than many bush beans, so choose a variety suited to your region's frost-free period.

General seed-starting guidance for US home gardens; timing depends on your local frost dates and variety. Page updated Aug 4, 2026.