Planting Guide and Seed Saving Notes for Soy Beans (Edamame)

Soy Beans (Glycine max)

A staple of Japanese cuisine, Edamame are unique soybeans that are harvested at the green stage. They are lightly boiled in water and eaten as a snack or appetizer by popping the beans out of the pods. An easy-to-grow, highly nutritious, delicious snack that is very popular with children.

Nutrients: dietary fiber, protein, vitamins A and C and riboflavin.

How to Grow Soy Beans from Seed

Bed Preparation

Beans are frost sensitive annuals that prefer full sun and rich, well-drained soil. To lessen the chances of disease and pests, alternate the location of bean plantings with a different crop each year.

Planting

Beans should be direct seeded since they do not transplant well. Plant beans outdoors once the danger of frost has passed and soil temperatures are above 50˚ F. Sow seeds 1" deep and 2-4” apart. Seeds will sprout in 8-16 days. Pole bean and half runner beans will need trellising, while bush beans should support themselves.

For a longer harvest, plant successions of bush beans every 3 weeks until mid-summer.

Harvest

Harvest soy beans in 70 days.

How to save Soy Bean Seeds

Bean flowers are perfect, self-pollinating and quite beautiful. They also almost never cross-pollinate, making beans an easy and satisfying seed to save. When planning to save bean seed, maintain at least 20 feet between varieties, and be careful planting two white seeded varieties side-by-side, if you intend to save seed, because crossing may occur but not be visible. It is always best to save seed from plants that are free from disease; this will ensure healthy genetics. Allow seedpods to dry on the plant and harvest when the seeds rattle inside. If you have a very wet fall, you can pull up the entire plant roots and all, and allow the beans to finish ripening and drying on the vine hanging somewhere dry and with good circulation. To get the best germination and longest shelf life of your seeds, you'll want to separate the seed from the dry pods. This prevents disease from setting in, and eliminates places for bugs to hide. The best way to do this is by winnowing your beans. You can do this by hand, but it will take a long time if you have many beans to clean. To clean a lot of seed, crush your very dry beans in a cloth or burlap sack and winnow the seeds from the chaff. This is best done outside, and by pouring your crushed beans from one bucket into another in front of a box fan or on a very windy day. The heavy beans will fall into the second bucket, while the dry chaff will blow away. Repeat the process until completely clean, which will likely take 3 or 4 rounds of winnowing.