How to grow soybean

Glycine max · edamame, vegetable soybean

Soybean (Glycine max) — a bushy annual legume grown as edamame, soybeans picked green before the pods ripen. Plants reach 45–60 cm and carry pods with two or three beans each. Soybean grows best in full sun. Water it about every 7 days while it grows.

Updated: November 4, 2026

When to sow soybean?

Sow straight into the bed after your last spring frost, once the soil has warmed.

The first harvest comes about 70 days after the shoots appear.

Frost dates · When to plant

Quick facts

Type	Vegetable
Latin name	Glycine max
Family	Fabaceae
Also called	edamame, vegetable soybean
Planted as	seed
How it is started	sown straight into the bed
Life span	grown for one season
Planting season	spring
Light	Full sun
Frost	does not tolerate frost
Soil for sowing	from 18 °C
Germination	10 days
Shoots to harvest	70 days
Grown in	Open ground

How long does it take to grow soybean?

From sowing to the first harvest: about 80 days (11 weeks). Shoots appear after about 10 days, then it takes about 70 days more to the first harvest.

Germination — 10 days
In the bed — 70 days

Step	Day
Sowing	0
Shoots appear	10
First harvest	80

Days count from the day of sowing or planting, by the figures of the card.

Soybean is number 26 of 63 on our list from the fastest crop to the slowest. Close to it on the list: parsley (76 days), moringa (80 days), carrot (84 days), chicory (85 days). Days to harvest: all vegetables, herbs and berries

Soybean care by growth stage

Open ground

Stage	Watering	Temperature	Feeding
Germination	every 2 days	—	—
Growth	every 7 days	—	—
Harvest	every 7 days	—	—

Growing notes

Light

Full sun, in a well-drained spot.

Soil

Warm, fertile, moist but well-drained soil kept free of weeds. Where soybeans have not grown before, treat the seed with soybean inoculant (Bradyrhizobium japonicum; pea and bean inoculant does not work); as a legume it needs no nitrogen fertiliser. Yellow leaves with green veins mean iron chlorosis, which a chelated iron feed between the rows corrects.

Care

Sow after the last frost, once the soil has warmed to about 18 °C (65 °F). Sow 2.5–4 cm deep and 5 cm apart, in rows 30–45 cm apart, and keep the soil moist until the seedlings are up in one to two weeks. Water about 25–40 mm a week, and do not let it go dry while the pods are filling, or blossoms drop and pods stay small. Pick when the pods are plump and bright green, about 70–90 days after sowing; once they yellow the beans turn starchy, and all the pods on a plant are ready within a week to ten days. Spider mites, stink bugs and beetles can feed on the plants.

Pests and diseases of Soybean

1 problem is recorded for soybean; it has a page with symptoms, treatment and prevention.

Pests

Two-spotted spider mite

Other plants of the Fabaceae family

Soybean belongs to Fabaceae; 7 other plants of this family have a guide here.

Plant lists it is in

Fast crops: harvest in 75 days or less

Sources

Figures checked against these sources.