grow soybeans

Growing Soybeans (Edamame)

Whether you call them edamame or soybeans, there is no shortage of information out there about them. Soy reduces thyroid function and promotes blood clots according to researchers at the National Center for Toxicological Research in Jefferson, Arkansas. Yet, according to an abstract in, soy, if eaten during childhood, may be a woman’s defense against breast cancer. As you can see, the verdict on soy is mixed. The one thing few people debate is that soybeans are a tasty treat and one of the few vegetables that kids will actually eat without being threatened with bodily harm!

Soybean Plant

Native to Asia, Australia and Africa, this is an annual plant that thrives in warm weather. Growth rate for the plant varies– from almost 8 inches to 6-1/2 feet.

Planting soybeans

Soybean plants require full sun and rich, fluffy soil. Plan to get the seeds into the ground after the last frost, when the soil has warmed to at least 65 degrees. Plant the seeds 2 inches deep, 6 inches apart.  If you are planting more than one row, space the rows 24 inches apart. Water the seeds right after planting and, if there is no rain, water again four days later.

Care of the growing soybean plant

The best fertilizer for soybeans is an all-purpose 10-10-10. Apply it at the rate suggested on the fertilizer label and always water after applying fertilizer.


Harvest the soybean pods when they are full. This generally occurs about 85 days after planting.

Pests and Diseases

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Mexican bean and Japanese beetles are attracted to the soybean plant and can be treated with a number of insecticides such as Sevin dust. If you don’t want to use chemicals (and I don’t blame you), try Azatrol Hydro Botanical Insecticide (available at or Milky Spore, which kills the Japanese beetle in the grub stage.

Two diseases common to all bean plants are bacterial and wilt disease. High heat and humidity are necessary for these diseases to occur and they can be prevented. Ensure the plants aren’t stressed by injury, high soil Ph, nutritional deficiencies and iron chlorosis. If the plant does become infected, it will require more water than normal because the root system is compromised. Fungicides listed for broad spectrum disease control are the recommended treatment (our favorite is a Bonide product, available at Amazon, here).