Skip to main content

Everything you need to know about growing and harvesting your own soybeans

Soybeans are in a lot of products we cook with and eat regularly, like soy sauce, edamame, soy milk, and tofu. However, we don’t typically think of soybeans as something that can be grown at home. That doesn’t have to be the case, though! You can easily add soybeans to your vegetable garden so you can have fresh, tasty soybeans whenever you want.

Eager to get started? Then you’re in luck, because we’re about to tell you everything you need to know about planting, caring for, and harvesting soybeans at home.

When and how to plant soybeans

Soybeans are native to southeast Asia, where the climate tends to be hot and humid. As you might have guessed from that, soybeans don’t tolerate cold, dry weather very well. Typically, they’re planted in late spring to early summer, although you may be able to grow them year-round if you have a greenhouse or live in a tropical or near-tropical region. Soybeans do take a while to grow, so if you have early winters or particularly cold falls it’s better to plant them in late spring.

For the best harvest, plant your soybeans in rich, well-draining soil where they’ll receive full sun. Although soybeans will tolerate partial shade and poor soil, you won’t see as large of a harvest. Plant the seeds roughly half an inch deep, and space them five to six inches apart. You can plant them closer together than five inches, but be prepared to thin them if more seeds sprout than anticipated.

Green soybean pods growing on the plant
Image used with permission by copyright holder

Caring for soybeans

Consistent moisture is important for soybeans to grow properly. Keep the soil moist but not soaking wet, as soybean seeds will sometimes crack or split if they get too wet. Instead, water them gently, spreading the water out over the entire patch of soil instead of focusing specifically on where the seeds are planted.

Once the seeds sprout, try to water them below the leaf level as much as possible. Soybeans are fuzzy plants and can easily develop problems if their leaves stay wet for too long. Additionally, overhead watering can sometimes knock flowers or seed pods off of the plant. A layer of mulch can help the soil retain water for longer, which reduces the amount of time you’ll need to spend watering your soybeans.

Soybeans don’t typically need any fertilizers, although adding compost to your soil if your soil is poor can be beneficial. If you do fertilize your soybeans, it’s important to avoid nitrogen-heavy fertilizers. Soybeans are nitrogen-fixing plants, meaning they absorb nitrogen from the air, which is added to the soil when their roots break down. Adding more nitrogen via a fertilizer can lead to a buildup of nitrogen in the soil, which causes nitrogen burn.

Green soybean pods growing on the plants
Image used with permission by copyright holder

Common problems when growing soybeans

Soybeans are sometimes bothered by pests who love these lovely legumes as much as we do. Depending on where you live, you may encounter damage from beetles and whiteflies or mammals such as deer, rabbits, and groundhogs. Mammals can often be kept out with fences, especially fences with noise-making attachments, while insects can be kept away with your pest repellent of choice.

Powdery mildew can also become an issue. It forms when the leaves are wet for an extended period, especially at night when the temperatures are cooler. Fungicides can help with mild cases and prevent it from spreading, but in more severe cases the best solution is to remove infected limbs or, in extreme cases, the entire plant.

Another potential issue comes from the shallow root system that soybeans have. If your soil is weak, overly loose, or you have a pet that likes to dig, you are at risk of your plant tipping over. A layer of mulch can help weigh your plant down and keep it grounded. Although soybeans stay fairly short and don’t typically need to be staked or supported, a stake may be useful if you live in an area with strong winds.

Mature brown soybean pods growing on brown, dry plants
Image used with permission by copyright holder

How and when to harvest soybeans

Soybeans can be harvested both as mature and immature pods. Immature pods are called edamame and can be harvested when they are two or three inches long. They should be a solid, bright green color. The pods should be fleshed out and full, with noticeable bumps where the seeds are. If the pods are thin without noticeable bumps, they likely aren’t ready.

Mature pods are ready for harvest when they’re solid brown or gray, depending on the variety. The leaves of the plant should be drying out and turning brown at the same time. They should still be fairly plump and full, though, and should be harvested before they dry out completely. To harvest mature or immature soybeans, gently but firmly twist, cut, or snap the pods off of the plant. Soybeans can be blanched and frozen or stored in a container in a cool, dark, dry place.

Soybeans are a delicious, versatile, and nutritious vegetable. Whether you use them as a protein-rich meat replacement or just like to crunch on edamame, these legumes are an excellent addition to any vegetable garden. No matter what you choose to do with them, this guide can help you start growing your very own soybean garden. You can even grow them in containers, although you’ll likely need more than one plant to fully satisfy your soybean cravings!

Editors' Recommendations

Cayla Leonard
Cayla Leonard is a writer from North Carolina who is passionate about plants.  She enjoys reading and writing fiction and…
Hardening off your seedlings as you bring them outside is crucial – here’s how to do it
Tips to help you successfully transplant your seedlings
Seedlings in plant tray

Even gloomy winter days can't stop enthusiastic gardeners. Unsurprisingly, many avid gardeners start their plants indoors when cold temperatures and unpredictable precipitation bar them from directly sowing their seeds outside. Still, the last frost date eventually comes around, and that's when it's time to bring those baby seedlings outside. Transporting seedlings outside is a simple process, but it still requires savvy coordination to prevent unwanted transplant shock. To help you keep your plants happy and healthy as they situate outside, we'll show you how to harden off seedlings.

What does hardening off seedlings mean?

Read more
The best (and worst) garlic companion plants
Plant your garlic next to these plants for the best results
A basket of freshly harvested garlic

Garlic is a flavorful addition to most dishes, and it can be a helpful addition to most gardens as well. Along with its strong flavor and smell comes the reported ability to repel pests by masking the scent of more palatable plants. This makes garlic an excellent companion plant for most vegetables and flowers, but what about the reverse? Which plants are good companions for garlic, and which are better planted elsewhere? This guide to garlic companion plants will answer all your questions so you can plan your next garden with confidence.
Fruits and vegetables

If you want to add garlic to your fruit or vegetable garden, then you’re in luck! Many fruits and vegetables make excellent garlic companion plants. Small root vegetables such as beets, radishes, and carrots are a good choice. They don’t take up much room and they can be planted alongside many other vegetables as well. Strawberries make great garlic companion plants.

Read more
Here’s what you should know about the updated USDA Hardiness Zone Map
These facts may help you as you begin your spring gardening
A person kneeling in a garden, removing a plant with a shovel

There’s major news in the gardening community: The USDA Hardiness Zone Map has been updated. If you’re a seasoned gardener, there’s a good chance that you’re familiar with this climate zone map, as it generally gives growers a good idea of which plants work in their area. But what does it mean for your spring garden if the map has been redrawn? Here’s what you need to know about the map, the change, and how it all impacts what you can grow in your yard. 
What is the USDA Hardiness Zone Map?

With the USDA Hardiness Zone Map, the U.S. Department of Agriculture splits the United States into 13 regions, using lowest average temperature ranges to designate specific planting zones. It’s simple to understand: Zone 1 is the coldest, whereas zone 13 is the warmest. Each zone is separated by 10-degree increments, but some gardeners like to get more granular and divide each zone into 5-degree increments (think zone 9A vs. zone 9b). 

Read more