As gardeners harvest the last of their beans or broccoli or corn, there is an opportunity to help feed the soil for next year by planting cover crops in the now empty spaces in the garden. A cover crop can also help break pest and disease cycles if you are not able to rotate your crops as often as needed. But you will need to act fast to get a crop established before cold temperatures set in!
For fall cover crop planting, you will also need to choose crops that can germinate and grow in cool weather. Winter rye, cereal rye, barley, triticale, winter wheat, oilseed radish, and hairy vetch can be planted now (early Sept.), either as a single crop or in mixtures. Seed can be broadcast over a prepared seedbed, or planted in close rows. Increase seeding rates for late-season planting, as the plants won’t have a chance to reach full size, and the goal is to achieve a thick stand.
South Dakota often experiences an early season frost followed by several more weeks of warmer temperatures; gardeners may choose to protect smaller areas of cover crop with frost blankets to take advantage of the extended growing season.
In the spring, as soon as the soil is dry enough to be worked, turn the cover crop under. You should allow a few weeks for the cover crop to decompose before planting your spring crops, especially if it was not winterkilled. Alternatively, if you are transplanting seedlings or planting large-seeded vegetables such as beans or corn, you may choose to leave the mowed or winter-killed cover crop on the surface as a mulch. However, don’t allow cover crops to go to seed – mow them if necessary. A scythe or string trimmer may be used for smaller areas.