Sow outside
Sow seeds 1 inch (25 mm) deep, and aim for 5 inches (13 cm) between plants once thinned. Water once at sowing, then keep evenly moist but not soggy. Cold wet soil rots the seed, so wait for warmth. Seedlings emerge in 5–12 days.
A sturdy bush bean grown for plump green seeds harvested young, boiled in the pod and popped out warm.
Glycine max · also called Vegetable soybean, Green soybean
Windows are counted from the average date of your last spring frost.
Store edamame is nearly always frozen; picked at the right stage from your own row it is sweeter and firmer. The plants also bank nitrogen in the soil for whatever follows them.
A little history. A soybean selected for large, tender seeds harvested at the immature green stage rather than dried. Long grown as a garden vegetable in East Asia, where it has been cultivated for centuries.
Sow seeds 1 inch (25 mm) deep, and aim for 5 inches (13 cm) between plants once thinned. Water once at sowing, then keep evenly moist but not soggy. Cold wet soil rots the seed, so wait for warmth. Seedlings emerge in 5–12 days.
Deep soak once or twice a week; never let it dry out during flowering and pod fill. Water when the top inch of soil feels dry. Aim for about 1 inch per week including rain.
Feed lightly at sowing only; skip nitrogen after that. What to use: compost worked into the bed, or a low-nitrogen 3–6-6 type fertilizer.
It's ready when pods are bright green, plump, and rounded, filling their full width, with seeds touching inside — usually all at once over 7–10 days. Pick individual plump pods by hand, or pull the whole plant and strip the pods indoors. Boil or steam within a day; sugars drop quickly after picking.
Refrigerate whole pods in a perforated bag up to 3 days. For longer keeping, blanch and freeze the same day they are picked.
Sow a second block 2–3 weeks after the first for a longer run; most varieties ripen their whole crop in one narrow window.
Foxtail Millet
A classic grain-and-legume pairing: edamame roots bank nitrogen that is released as those roots break down, so the millet or grain crop following in that ground finds a richer bed. Grown side by side, the fine fibrous millet roots and the deeper bean taproot draw from different layers rather than competing.
Sweet Corn
Corn feeds heavily near the surface while edamame sends a taproot deeper, so the two share a bed without fighting over water. Keep the beans on the sunny south side of the corn block so they are not shaded out.
Cucumber
Cucumber vines run along the ground between bean rows, shading soil and holding moisture where edamame roots sit. Give each crop its own watering pass and pick beans from the outside of the row to avoid trampling vines.
Sweet Alyssum
Its tiny nectar-rich flowers draw in hoverflies and tiny parasitic wasps, whose larvae hunt aphids on bean foliage. Sow a low band along the row edge where it will not be shaded out by the bushes.
French Marigold
French marigolds have been shown to reduce root-knot nematodes, but only when planted thickly across the ground or turned into the soil at season's end — a few flowers at the bed edge do nothing. Treat it as a pre-season soil measure rather than a companion for the current bean crop.
Summer Savory
Gardeners have long grown summer savory at the end of bean rows, and it is said to reduce bean beetle damage. No mechanism has been demonstrated, but the herb is compact, harmless to the beans, and useful in the kitchen alongside them.
Fennel
Fennel roots release compounds that reliably stunt most garden vegetables, beans included. Grow it in its own corner or a pot — planted well away, its flat flower heads feed hoverflies and tiny parasitic wasps, so it still earns garden space.
Onion
Old charts keep beans and the onion family apart, and edamame is treated the same way. No mechanism has been demonstrated in trials, so if bed space is tight, separate them by a row and watch your own results rather than reworking the whole plan.
Garlic
Gardeners have long avoided planting beans beside garlic. The pairing rests on tradition rather than evidence, though the practical point stands: garlic is harvested mid-summer, and digging it disturbs bean roots that are flowering at that moment.
Give the pea and bean family 2 years away from this spot before any of its relatives return.
The cabbage family, the beet family or grasses and grains thrive in this ground next season.
A giver — it leaves nitrogen behind in its roots for the next season. Keep pea and bean family crops out of this ground for 2 years. Follow with the cabbage family, with beets, chard, or quinoa, or with a grain such as millet or wheat, all of which use that nitrogen well.