USING COVER CROPS
by Sue McDavid
UCCE Master Gardener of El Dorado County
When the word "crops" is used, many immediately think of something edible. However, cover crops are used to replenish soil so that during the next growing season, healthy and vigorous plants will be the norm. Fall is a perfect time to begin sowing cover crops, also sometimes referred to as a green manure.
Healthy plants begin with healthy soil. That's why after one growing season ends (in this case, spring and summer), gardeners need to revitalize the soil. Cover crops include legumes and grasses which grow quickly and pump nutrients back into the soil.
Once the spring and summer harvest is over, either pull or cut off at the soil line any plants that are finished for the season. Planting a cover crop in a bare garden plot or bed will not only help to revitalize the soil, it will help suppress weeds. In addition, they increase the amount of organic matter in the soil and prevent erosion and soil compaction. Plus, they attract beneficial insects both above and below the soil, including bees and earthworms.
When to Plant Cover Crops
Typically, seeds for cover crops are planted a few weeks before the first frost. This will give them enough time to establish themselves before really cold weather arrives. Rake the topsoil and spread the seed over it. Then, rake the seeds into the soil and wait for the plants to grow. Keep the ground well-watered until the rain arrives. Once seeds germinate and the plants grow, nothing else needs to be done until spring.
When to Cut Cover CropsWhen it is about 6-8 weeks before the time of the last expected frost, it is time to kill the cover crops; do this before they flower. Use a mower, weed trimmer or hand pruners to cut them down at the base close to the soil. Once the stems and leaves have dried, dig them into the soil. You won't be able to plant in the area right away; wait a few weeks to a month to give the dead plants time to decompose.
What Cover Crops to UseThere are many options to choose from. Clover, alfalfa and legumes are all nitrogen-fixing cover crops, taking nitrogen from the air and returning it to the soil.
Buckwheat is another cover crop that is fast-growing and very easy to cultivate. It is cold-tolerant, attracts beneficial insects and is ideal for replenishing nutrients in depleted soil. Buckwheat plants can grow up to nearly 2 feet in a single month if conditions are right.
Barley is another fast-growing plant and it is great at capturing nitrogen in the soil that may have been left over from crops planted earlier in the year.
Different cover crops can also be planted together to help rebuild soil. Just remember to remove all cover crops by at least mid-April because the longer they sit in the ground, the more difficult they are to remove.
Give the garden the best start for next spring by taking steps now to replenish the soil. A bit of work will pay off when you see how freely the soil can be worked when the next growing season arrives.
October is a busy month for Master Gardener public education classes! “Olives: From Garden to Table” will be at the Cameron Park Community Center, 9am to noon, on October 11. “Saturdays with Barry” continues at the Sherwood Demonstration Garden in Placerville, 9 to 11am, on October 14. “Replacing Your Lawn” will be at the Government Center Hearing Room, Bldg C, Placerville, 9am to noon, on October 14. Classes are free.
UCCE Master Gardeners of El Dorado County are available to answer home gardening questions Tuesday through Friday, 9:00 a.m. to noon, by calling (530) 621-5512. Walk-ins are welcome at our office, located at 311 Fair Lane in Placerville. For more information about our public education classes and activities, go to our UCCE Master Gardeners of El Dorado County website at http://mgeldorado.ucanr.edu. Sign up to receive our online notices and e-newsletter at http://ucanr.edu/master gardener e-news. You can also find us on Facebook.