A few summers ago, my wife casually mentioned that she needed a bag of buckwheat. “No problem,” I responded. ” I’ll pick up a bag the next time I’m in the grocery store.” I figured she must have been reading my mind as I had just hours before been thinking that it had been too long since I had sat down in front of a stack of buckwheat pancakes smothered in warm maple syrup. Needless to say, the conversation went downhill after I mentioned my pent up hunger for buckwheat pancakes. She curtly informed me that she wasn’t talking about buckwheat flour to make pancakes but buckwheat seeds to be used to plant in the garden to fill in some bare spots. Well, that stack of pancakes evaporated right before my eyes. I came to the conclusion that this buckwheat journey she had in mind was going to be a garden journey not a culinary breakfast journey. I was about to find out the benefits of growing buckwheat in the garden as a summer cover crop.
As it turns out buckwheat (Fagopyrum sagittatum) has been grown in America since colonial days, and the crop once was common on farms in the northeastern and north central United States. A couple of farmers whose names you may recognize, George Washington and Thomas Jefferson, corresponded with each other about the benefits of growing buckwheat.
Unlike many cover crops, buckwheat is a broadleaf-non-leguminous, frost-sensitive plant that is ideal for growing in the summer. It can be planted between corn rows or after spring crops (such as lettuce, peas and potatoes) have been removed from the garden or it may be interplanted with other vegetables like winter squash.
Buckwheat has a number of admirable attributes: it is not picky about its environment, it doesn’t require a lot of water, and it tolerates poor soil fertility and acid soils (low pH down to around 5.0) . However, buckwheat does NOT like shade or saturated soils. Buckwheat is a fast germinator (4-5 days) and can reach a full mature size of 2-3 feet within 5-6 weeks. This rapid growth turns buckwheat into a weed suppressor because it forms a shade covering that impairs the growth of weeds. For this reason it is often referred to as a “Smother Crop.”
In addition to smothering out weeds, buckwheat will do all kinds of good things for your soil: it will protect the soil surface from wind and water erosion, improve the general physical condition (tilth) of the soil, improve soil aeration and structure, promote microbial growth, help retain soil moisture and reduce soil crusting.
Buckwheat also captures nutrients — particularly phosphorus and calcium — from the soil that could otherwise be lost from leaching out. The captured nutrients are then released to later crops as the buckwheat residue breaks down. The roots of the plants produce mild acids that activate slow-releasing organic fertilizers, such as rock phosphate. Buckwheat’s dense fibrous root cluster in the top 10 inches of the soil also prevents erosion and nutrient loss by slowing water runoff from bare soil.
The white flower clusters of buckwheat are very attractive to insects. An article published by the Virginia Cooperative Extension Office suggests that buckwheat is the ultimate insectary plant. (For more information on the insectary concept, see The Garden Shed article titled “Insectary?”). Buckwheat attracts a host of beneficial insects and pollinators that include: parasitic wasps, minute pirate bugs, hover flies (syrphid flies), native bees and honey bees.
Research underway at the USDA suggests that buckwheat also attracts a small fly (Trichopoda pennipes) that is a parasitoid of stink bugs. That alone is a benefit that makes buckwheat an outstanding cover crop option!
Buckwheat can be planted anytime after the last spring frost (May 15th) and right up until late summer (until about 60 days before the first killing frost — October 15). To plant buckwheat, broadcast a cup of seed over 100 square feet (or 1 pound per 300 to 500 square feet; or 70 to 100 pounds per acre) and rake it in at a depth of 0.5 to 1.5 inches. It will sprout, grow and begin to bloom within six to seven weeks.
If you are only growing one crop, the buckwheat plants should be cut down within 10 days after the plant begins to bloom, to prevent the plants from reseeding and becoming a weed. However, if you are planning a sequential planting or using the buckwheat crop to attract beneficial insects, the plants should be allowed to bloom for at least 20 days, the time needed for the beneficial insects to produce a new generation.
The major pest that afflicts buckwheat is deer, so you may want to protect your crop by fencing in the area, or you can occasionally spray your buckwheat with a deer repellent.
Buckwheat is one of the easiest cover crops to grow, and is one of the best for preventing depletion of soil nutrients and for adding organic matter to the soil. Buckwheat has the additional value of attracting beneficial insects. To say the least, I am hooked on buckwheat!
Thanks for stopping by The Garden Shed. We hope to see you again next month!
“Buckwheat Cover Crop Handbook,” Cornell University, http://www.hort.cornell.edu/bjorkman/lab/buck/handbook/intro.php
“Buckwheat,” United States Department of Agricultural (USDA) Plant Guide, https://plants.usda.gov/plantguide/pdf/pg_faes2.pdf
“Buckwheat: A Multi-Purpose, Short-Season Alternative,”University of Missouri Extension, Publication No. G4306, http://extension.missouri.edu/p/G4306
“Improving Pest Management with Farmscaping,” Virginia Cooperative Extension Publication ENTO-52NP, http://www.pubs.ext.vt.edu/ENTO/ENTO-52/ENTO-52.html
“Crop Rotation and Soil Tilth,” Sustainable Agriculture Research & Education (SARE), http://www.sare.org/Learning-Center/Books/Crop-Rotation-on-Organic-Farms/Text-Version/Physical-and-Biological-Processes-In-Crop-Production/Crop-Rotation-and-Soil-Tilth
“Green Alternatives May Control Stink Bugs and Help Monarch Butterflies,” Entomology Today, https://entomologytoday.org/2014/11/06/green-alternatives-may-control-stink-bugs-and-help-monarch-butterflies/