Cover crops are generally something home gardeners think of as being used only in large-scale growing operations—or don’t think of at all! However, the benefits of cover crop usage should entice home gardeners to experiment with them. 

Cover crops are beneficial in many ways. They start by serving as a green mulch in your garden - they aid in weed suppression and erosion prevention. In large-scale operations cover crops are often used in walkways or as forage for animals. Some varieties of cover crops attract pollinators to the garden when they flower. Finally, and maybe most importantly, cover crops help with the health of your soil. Legume cover crops such as peas, vetch or clover fix nitrogen in the soil. The living roots of cover crops help maintain soil moisture, hold onto nutrients and support soil microorganisms. When the cover crop is eventually worked into the soil as a green manure, it further supports soil health by adding nutrients as the plant material decomposes.

The most daunting part of experimenting with cover crops is choosing the type of crop to use. The type of cover crop you plant depends on when you can plant it and what you are trying to achieve with the crop - nitrogen fixation, weed suppression, etc. Cover crops can be planted in spring (before warm-weather crops are planted), between plantings and after harvest. A winter-kill cover crop planted in the fall is recommended if you are trying cover crops in your home garden for the first time. Examples of cover crops that will die over winter are: buckwheat, oats, peas, berseem clover and tillage radish.

General cover crop tips

• Cover crop seeds can be found at garden centers or online seed retailers.

• Plant cover crop seed densely; smaller areas can be planted by hand.

• Follow good crop rotation practices with cover crops. For example, don’t plant tillage radish in an area where other brassicas were harvested or will be planted the following spring.

• Mow or cut down flowering cover crops to prevent them from self-seeding.

• Dead plant material can be turned over in the spring or fall. 

• If plant material doesn’t die over winter, wait 2-3 weeks after turning over the green material before planting new seeds or transplants.

The Midwest Cover Crops Council has a fabulous tool designed for large-scale growers that can also be used by home gardeners. It includes detailed information on many varieties of cover crops.

Cover Crop Decision Tool

For more information about cover crops in Minnesota, visit:

https://extension.umn.edu/cover-crops-and-soil-health/cover-crop-selection-vegetable-growers

Photo credits: University of Minnesota Extension (1, 2, 3)