I've never thought about growing soybeans until I was offered edamame as an appetizer while dining out for lunch.
I've known about edamame for some time. The word, which is really a fancy-schmancy way of saying "boiled young soybeans" describes this podded bean that is used to make tofu, soy milk and other vegetarian and dairy free products. (An Asian vegetable, edamame actually translates to "beans on branches"). I am not a vegetarian, but I am a huge fan of vegetables and am especially happy if I can grow and harvest dinner from my garden.
Edamame has become so popular in recent years that bags of frozen soybeans, with or without their pods, can be found in most grocery stores. Going one step further, they also can be grown in our backyard gardens.
The issue in our area is our limited hot growing season. Unlike tomatoes and peppers, which also need a long season, soybeans don't transplant well, so they can't be started ahead of time indoors. They also like warm soil, at least 55 to 60 degrees Fahrenheit, which means we shouldn't be planting them before late May and early June, although early warming of the soil can be accomplished by creating a plastic hoop house or layer of clear plastic on the planting row.
To make it easier, the magic of horticulture has come through for us and now short season varieties are available from seed. An Internet search revealed 85-day seeds simply called 'Edamame' at Renee's Garden Seeds (reneesgarden.com), a 65-70 day variety called 'Early Hakucho' at George W. Park Seeds (parkseeds.com) and a 65-day variety called 'Green Pearls' at W. Atlee Burpee & Co. (www.burpee.com). I prefer to support our local garden centers, so don't be afraid to ask if they can get the seeds.
Seeds should be planted in full sun about three inches apart with two feet between rows. Help the plants along by sprinkling the furrow with a legume inoculant to enable the plant to draw nitrogen from the air. Plant the seeds about an inch under the soil surface and keep the soil moist enough that it doesn't get crusty but not so wet they are sitting in mud. It usually takes about five to 10 days for the young seedlings to emerge depending on the warmth of the soil. When the plants begin to flower, you can apply a little fertilizer.
Unlike bush beans that flower and produce over several weeks, all of the beans on a single edamame plant mature at the same time. This means, if you are growing them solely to harvest and freeze, go ahead and plant them all at once. But if you want beans to snack on fresh from the garden, plant seeds every week or so to ensure a successive harvest over a longer period of time.
Beans should be harvested when the beans fill out a bit, but before the pods are completely mature. Soybeans will begin to lose their nutrients and their flavor once they reach maturity.
According to the National Garden Bureau's instructions for harvesting soybeans, the darker the color of the pods, the better their flavor. Pod color is determined by how much sunlight the plants receive. The NGB also suggests harvesting in the evening for the best flavor.
Once harvested and washed, boil the pods for about three minutes. It's OK to add a little salt to the water, but not mandatory if salt is an issue in your diet. If the bean pods are frozen, it might take a couple extra minutes.
Although the pods are edible, they are stringy and chewy and not the best culinary treat. The beans can be removed from the pods before cooking to add to dishes such as stir-fry or soup, but my favorite way to eat them is to put the pod in my mouth while holding onto one end and then pull the pod out while popping out the seeds.
Nutritionally, edamame is an extremely healthy snack. One-half cup of shelled beans (or one and one-eighth cup in the pods) is 120 calories, 9 grams of fiber and only 2.5 grams of fat, which is mostly polyunsaturated and contains omega-3 fatty acids. This amount of beans also contains 11 grams of protein and only 15 mgs. sodium.
I have a favorite way of preparing them for snacking. Once my serving of beans has been boiled, I like to saute them in a teaspoon of olive oil and a couple cloves of minced garlic. Since they are so low in sodium, I also can get away with a little sprinkling of sea salt.