Growing a cover crop in the garden is becoming a popular trend. It is one of the most natural and affordable ways to improve the quality of your soil.

One of the best ways to improve your soil is to add organic matter, and this is where growing cover crops can help. It’s a popular trend in gardening (and farming) today. A cover crop:

Adds nutrients. The deep roots of cover crops absorb and pump up nutrients from deep in the soil that your garden plants can’t reach. These nutrients are then slowly released to your plants. As a bonus, some cover crops convert nitrogen from the air into nitrogen in the soil.

Holds onto nutrients. Roots of cover crops bind onto nutrients in the soil, preventing them from leaching away.

Boosts soil moisture. A soil covered with a cover crop loses less water from evaporation compared to an exposed soil. Cover crops improve soil structure, allowing rain to infiltrate, rather than run off the land.  Cover crops collect snow over winter, which can melt into your soil.

Loosens hard ground. Roots of cover crops penetrate compacted soils, breaking them up. This allows for better drainage and aeration.

Reduces erosion. Cover crops blanket the land, preventing the soil from blowing or washing away.

Reduces weeds. Cover crops smother and kill weed seedlings.

Lots of different grains and legumes may be used as cover crops. At this time of year, winter rye (Secale cereale) is preferred. Sow it anytime this month (the sooner, the better). The rye will grow vigorously this fall and begin growing again in spring.

Rye is best sown on land that will be planted in warm-season crops (tomato, squash and cucumber) next spring. Sow the rye seed in areas of the garden that are done producing or between rows of crops that are still producing.

In early May, mow and cultivate the rye into the soil. No-till gardeners can spray the grass with glyphosate (Roundup) to kill it. Give it a couple weeks to break down and then plant your crops at the end of May.

Be aware that rye emits chemicals as it decomposes that suppress the germination of weeds and small-seeded vegetables (lettuce and carrots) in spring. Large-seeded vegetables and transplants are much less affected.

Winter rye seed is available from catalogs and farm supply stores. Sow it at 3 ounces per 100 square feet.

Written by Tom Kalb, Extension Horticulturist, North Dakota State University.  Source: Sustainable Agriculture Research and Education. 2007. Managing Cover Crops Profitably. Photos were made available under Creative Commons licenses specified by the photographers: Chiot’s Run and Dwight Sipler.