Need a summer cover crop in the garden? A fast-growing crop, buckwheat is a succulent that can be grown as a green manure crop, adding nutrients and organic matter to the soil. It improves the tilth of the soil, preparing the garden bed for transplants. It is very efficient at taking up phosphorus from the soil and storing it in its tissues, making it more bio-available for subsequent crops.
Buckwheat seed germinates within days of planting, especially when the soil temperature is warmer than 55 degrees. Buckwheat is fast growing broadleaf. Its quick germination and vigorous growth canopy make it an excellent smother crop for weeds. Its heavy flower set and nectar is very attractive to pollinators and other beneficial insects and provides excellent habitat; a “pollinator pasture,”especially for honey bees!
Buckwheat provides a protective canopy over the garden’s soil surface between early spring harvests and fall planted crops. Its fast growth makes it ideal for planting in places that might otherwise be left bare over the summer. Buckwheat will begin to flower at about five weeks, when it reaches two to four feet high.
It will continue to flower for the rest of the season and sets seed two to three weeks after flowering. Mowing will prevent the seeds from maturing. Mature seeds may germinate and become a weed under certain circumstances but most consider buckwheat volunteers a “good weed” because it is easy to kill, competes with problematic weeds, provides green manure benefits, and pollinators love it. Buckwheat is frost-sensitive and will winter-kill naturally.
Planting buckwheat In the spring or early summer by scatter the seed over the garden bed at about one pound per 500 square feet or three ounces per 100 square feet. Rake and water it in to get good soil-to-seed contact for quick germination.
Buckwheat tolerates poor fertility and doesn't require much water. It is drought tolerant; plants may appear wilted on hot summer afternoons but should recover overnight. Buckwheat succeeds in many less-than-ideal places in the garden but does not do well if shaded or when planted in wet, saturated soils. Buckwheat prefers a soil pH of 5.0-7.0.
To avoid setting mature seed, mow or cut down buckwheat within two weeks of first flowering. Turning buckwheat plants into the soil will begin decomposition. Allow three weeks for decomposition before planting a subsequent vegetable crop.