At Green Bridge Growers, we're big fans of cover crops. Cover crops are crops farmers or gardeners grow in their field to help enrich the soil when they’re not currently growing any crops there. They help suppress weeds, as well as improve soil quality and structure. This year, we piloted growing buckwheat as a cover crop. You may have heard of buckwheat as a grain that you can make into flour. But what if I told you buckwheat can also be used as a cover crop?
Buckwheat is a fast-growing cover crop. It reaches maturity in 70-90 days, and its flowers can attract beneficial insects. It's also better at extracting phosphorus from the soil than most other plants. Also, buckwheat can regrow after mowing if it's cut before it reaches 25 percent bloom. It’s also very effective at suppressing weeds, which it does through shading and competition.
It is usually used as a mid-summer cover crop. In the Midwest and Northeast, it’s often planted after the harvest of early vegetable crops, and then followed by a fall vegetable, winter grain, or cool-season cover crop.
If buckwheat is allowed to blossom, then it can also attract beneficial insects that parasitize pests. These beneficial insects include hover flies, predatory wasps, and ladybugs, among others.
We actually grew buckwheat in our fields this summer—25 pounds of it to be exact. We planted it on July 25, and it took 10 days for it to germinate. And it did an absolutely incredible job attracting bees. When we went to mow it down for the fall, there were thousands of bees on the buckwheat. We didn't have the heart to cut it down with so many bees feasting on it, so we decided to leave it alone for a few days. We finally mowed it down once all the bees were gone. But it sure was a sight to behold.
Growing buckwheat
In order for buckwheat to sprout, the soil needs to be 70°F or above. It grows best in moist, well-drained soil, and it does not tolerate drought or frost very well. Because it doesn't tolerate frost, it shouldn't be planted in the fall.
Buckwheat is usually planted 1 inch deep, but that can be adjusted depending on the moisture and soil. For optimal weed suppression, plant the buckwheat in narrow rows 6 inches apart.
Buckwheat prefers soils with a neutral or slightly acidic pH. It doesn't do very well in alkaline soil. It does well with modest fertility, and doesn't like too much nitrogen.
When it's time to kill off the buckwheat for the winter, mow or plow under it. The resulting decaying organic matter will enrich the soil with nitrogen and improve the moisture holding capacity of the soil.
I hope this encourages you to plant some buckwheat in your garden next summer as a cover crop. Let us know how it goes!
-Chris Tidmarsh
Additional resources:
https://www.sare.org/publications/managing-cover-crops-profitably/nonlegume-cover-crops/buckwheat/
Photo credit: Jorge Lorza, NRCS – USDA