Buckwheat • Quick & Easy Summer Insectary/Smother Crop
Background drawn in part from Growing for Marketmagazine
Quick, Easy, Summertime Solution
Buckwheat (Fagopyrum esculentum) is among the easiest and fastest summer cover crops. It's grown mainly to smother weeds and loosen soil, and it also helps interrupt disease cycles and gives beneficial organisms a home. A warm-season crop, it fits neatly between spring and fall vegetables, for example as a lead-in to fall carrots sown in late July or early August. It's useful on new ground as well: sown on freshly turned sod, it speeds the breakdown of the sod for a fall or next-year planting of vegetables, flowers or berries.
Buckwheat grows 2–4' tall, with heart-shaped leaves and white, pink or red flowers. Sow it once the soil is warm enough for germination, roughly 50–55°F (10–13°C) or above. It comes up within a few days and starts blooming in about a month, offering plenty of nectar for honey bees and native pollinators, and it can also serve as a trap crop for thrips.
Seed matures 2–3 weeks after bloom; left in the field, it feeds ground birds such as quail and pheasant. A light frost kills buckwheat. It doesn't add nitrogen and adds little organic matter, but it takes up some phosphorus and improves the top few inches of soil, which helps the vegetables, flowers or fruit that follow, whether direct-sown or transplanted.
Tips for Getting Your Buckwheat Crop Up Before the Weeds
For weed control, the goal is to get buckwheat established quickly so it outgrows the weeds. These tips help you get a strong stand and manage it to benefit the crops that follow.
- Before sowing, till under weeds and old crop residue and give it about a week to break down so it won't interfere with germination. Break up large clods and make the seedbed as fine as you can.
- Let the soil warm, and let it dry if it has been wet, since buckwheat seed rots readily in cold, soggy soil. If it is very dry, water to about 1" deep before sowing. In the Northeast, late May or early June is usually warm enough. Good moisture helps germination, and shallow harrowing gives the light covering the seed needs.
- Cover the seed just barely: not too deep, but not left on the surface. Running a cultipacker over the bed afterward firms the soil, holds in moisture and gives good seed-to-soil contact.
- Broadcast by hand at about 60 lb per acre, spreading it evenly, or drill it less than 1" deep at about 50 lb per acre. Where weeds are heavy, or if you want a dense stand with no gaps, raise the rate; many growers sow 80 lb per acre or more.
- After emergence, look for thin spots and reseed any bare patch more than about 1' across. Weeds that grow in the gaps will set seed and keep the weed cycle going, undoing much of the benefit.
- Expect flowers about 4–6 weeks after sowing. If you need the ground for a fall crop, mow before seed matures. If the field can wait until next year, you can let the buckwheat reseed and grow a second stand the same season. Since it won't survive frost, mow it and sow a winter cover crop in late summer or fall if you want the ground covered over winter.
Learn More
- Buckwheat as a cover crop in organic farming: USDA NIFA eXtension
- Buckwheat cover crop handbook: Cornell University
- Cover crop database, buckwheat summary: University of CA Sustainable Agriculture Research & Education Program
- Cover crops for home gardens and raised beds (article)
- Ending cover crops in organic systems (article)
- Cover crop comparison: sowing seasons, germination temperatures and growth rates (comparison chart)
