Buckwheat is an amazing cover crop that is often overlooked. While there are many great cover crop options, buckwheat has several advantageous and valuable characteristics worth keeping around. Its strongest advantage is its quick growth. Exactly how long you should grow it for really depends on how quickly it flowers. This can vary depending on local weather conditions. It can mature in 70-90 days but should be terminated within 7-10 days of flowering. It is important to terminate buckwheat cover crops before seeds have a chance to mature. If left to seed, buckwheat can quickly become a weed.
It matures to about 24-36 inches tall and 18-24 inches wide and is ideally sown as a winter cover crop. Similar to Daikon radish and yellow mustard, buckwheat produces a thick and deep taproot known to help increase tilth and aeration for overly compacted, heavy soils. Common buckwheat shares many of the same tolerances and ecological benefits as wild buckwheat while still boasting just as many blooms as any wildflower or ornamental.
Advantages of Growing Buckwheat Cover Crops
Weed Suppression - Buckwheat's quick growth habit makes this crop valuable at smothering weeds by out-competing them for space, water, and light. If you have an overgrown garden that you want to take control of again, consider utilizing buckwheat to interrupt weedy growth. Start by preparing the area. Cut down the overgrown weeds and till the soil. This will weaken the existing weeds hold on the area. Then, plant your buckwheat cover crop. Be sure to terminate once flowering starts. Do not allow hard seeds to mature, or you will be faced with a weed patch once again. We do not recommend using buckwheat as an intercrop with plants meant for harvesting.
Phosphorus Scavenger - Buckwheat is unique from other cover crops as it acts as a phosphorus nutrient scavenger. As it grows, the roots pull phosphorus into the root zone for your future crops to benefit from. The SARE reports that buckwheat cover crops are 3 times as effective as barley and 10 times more effective than the poorest cereal grain phosphorus scavenger-rye.
Rejuvenates Poor Soils - Its quick growth makes it a tremendous tool in rejuvenating poor soils depleted of nutrients, tilth, and poor soil structure. While other cover crops require many weeks to develop enough beneficial growth, buckwheat thrives in very little time. It is both quick to grow and quick to decompose. This combination makes it a perfect cover crop for growing in the spring, summer, or fall months between crops. Because of its quick growth rate, it doesn’t always pair well with other cover crop seeds that require much more time to grow foliage and flowers.
Terminating Buckwheat Cover Crops
Buckwheat is tender to frost and will winter-kill. However, you must pay attention to its flowers. Do not allow seeds to form. If this crop is not grown within a few weeks of your first fall frost, you may need to terminate it with other means. Allowing seeds to develop will lead to a weed patch. SARE reports, “Buckwheat will regrow after mowing if cut before it reaches 25 percent bloom. It also can be lightly tilled after the midpoint of its long flowering period to reseed a second crop. Some growers bring new land into production by raising three successive buckwheat crops this way.” Be sure to plan ahead and utilize tilling, smothering, or tarping to kill your cover crop if frost is not expected in time.