Crimson Clover - illustration by Helen KrayenhoffIt may be cold out, but it’s not too late to give something back to your garden by planting a cover crop. Cover crops will give your soil that extra boost before you begin planting in spring.

Fava Beans ~ Fava beans accumulate large quantities of nitrogen, which is available to subsequent crops. They have deep taproots that help open up heavy, compacted soils. The leaves decompose quickly but the stems break down slower and help to loosen clay soil. You can eat the beans in spring. We also sell the broad bean, which is the favored edible Fava variety.

Annual Ryegrass ~ Ryegrass is quick to germinate and is very vigorous. It grows well in our Bay Area clay and can tolerate wet soil. In the spring, mow or till it under, then the residue breaks down quickly adding needed organic material to improve soil structure and drainage.

Crimson Clover ~ Crimson clover also fixes nitrogen (the process of making N available to the roots) and produces lots of great humus to work back into the soil. Crimson clover is beautiful and is a great beneficial insect attractant. 

These winter cover crops not only add nitrogen and organic material to your soil, but they also protect the soil from erosion and help control weed seed germination and growth. Organic matter will help beneficial soil organisms such as earthworms and fungi. Their by-products are in turn used by other organisms in the soil. 

Fava beans take a little more work but it is worth it. They should be treated with a bacterial inoculant and then poked-in about 1 1/2 inches deep. The other cover crops are fairly easy to plant, just spread the seeds and rake a little soil over them. Your soil will appreciate it.