Cover Crops For the Home Garden
by Larry G. Campbell
Cover crops are plants grown to cover the soil during idle periods in the garden such as in the fall. October is a good time to consider the value of a cover crop for our home gardens.
Cover crops provide many benefits for the home garden such as:
- Reduce soil erosion
- Adds biomass which improves soil structure
- Adds nutrients (ave. 100 lbs nitrogen per acre per year for legumes)
- Improve microbiotic activity in soil
- Weed reduction (“Smother Crop”)
- Capture leftover fertilizer
- Reduce soil temperature fluctuations
- Habitat for beneficial insects.
Cover crops are grouped into two categories: warm season and cool season. Warm season cover crops are planted between April 15 and June 15. Buckwheat is a typical warm season cover crop. Cool season cover crops are planted between September 15 and October 15. Grain crops such as cereal rye, winter wheat, and oats fall into this category.
Home gardeners should consider planting a cool season cover crop on their gardens each fall. Cereal rye and winter wheat would be good choices.
Cereal rye also called winter rye can be planted later than any other cover crop. Typically it is planted August through late October. However, during a warm, mild fall it can sometimes be successfully planted in early November.
Cereal rye is the most winter-hardy of the cereal grains. Uniquely it is allelopathic which means that it secretes a chemical into the surrounding soil that suppresses the germination of other plant seeds. This makes it valuable for suppressing the growth of winter annuals in the garden. This affect will dissipate upon incorporation of the rye into the soil in the spring.
Winter rye can grow rapidly in the spring and reach a height of six feet if left uncut. Care should be taken to till it into the soil before it gets too tall.
Cereal rye should be planted at two to three pounds per 1,000 square feet. A light raking of the seed will insure good seed to soil contact.
Winter wheat grows quickly in the fall and is more leafy than rye. It should be planted late August through mid-October at two to three pounds per 1,000 square feet.
Winter wheat is less tolerant of soil conditions than is rye. It prefers fertile soil and does not tolerate wet or low pH soils.
Cereal grains can be combined with legumes to make a good cover crop mix. This mix combines the soil covering and nitrogen capturing ability of cereal grains with the nitrogen fixing ability of legumes.
A typical mix is cereal rye and hairy vetch. Hairy vetch fixes more nitrogen and produces more biomass than most legumes. When planted with rye, it will vine up the rye making it easier to cut it the spring. Plant at 1.75 pounds per 1,000 square feet rye to .75 pounds hairy vetch per 1,000 square feet.
Other good mixes include: crimson clover and wheat and oats with crimson clover.