Even small gardens benefit from the growing of cover crops, or “green manures.”
The cultivating, weeding, tilling, harvesting and foot traffic of most home gardens has a tendency to destroy soil structure. Planting cover crops is an easy way to revitalize the soil and help with soil tilth and ensuing plant growth.
Cover crops are grown, then tilled into the soil after they reach their peak maturity, instead of being removed from the garden area. They provide a number of advantages for the otherwise unused space during your garden’s off-season.
Cover crops help gardeners retain soil and lessen erosion by slowing the runoff of water. They also reduce mineral leaching and compaction, and they suppress the growth of perennial and winter annual weeds.
The top growth adds organic matter when it is tilled into the garden soil, and the cover crops’ root system also provides organic matter and helps improve air and water movement in the soil.
Finding success when growing cover crops requires choosing the right crop, seeding it at the right time and managing it properly.
There are many traditional cover crops to consider, including annual ryegrass and Austrian winter pea, a legume. Oats, white clover, sweet clover, winter rye, hairy vetch and buckwheat can also be grown as cover crops.
Grasses are a little easier to grow than legumes, such as clover, because they germinate more quickly and do not require inoculation. (Legumes grow better if their seeds are mixed with rhizobium bacteria, sold as a powder.) Small-seeded crops can be more difficult to establish than large-seeded plants, such as oats and buckwheat.
In poorly drained areas, including gardens with a high percentage of clay soil, like many in our area, grasses may be easier to get started. Winter rye and ryegrass grow in a very dense habit and are much more effective at shading out weeds than oats or small-seeded legumes.
• University of California-certified master gardeners are available to answer gardening questions from 9 a.m. to noon Tuesdays, Wednesdays and Thursdays at 953-6112 or email@example.com. Questions for Heather Hamilton can be sent to firstname.lastname@example.org.