Cover Crops to Prepare Next Summer’s Garden


by Linda Carloni, Alameda Backyard Growers
October 12, 2017

Fall has arrived, and the end of our warm-season vegetable gardens has arrived. Alameda has such a moderate climate that we can plant cool-season gardens, but many gardeners choose to give their vegetable plots a rest in the rainy season.

When a garden isn’t producing a food crop, it can profit from a cover crop, which:

  • Adds nitrogen, an important plant nutrient, to the soil;
  • Adds organic matter, that also increases the soil’s ability to hold water and makes nutrients more available to plants.

This is important in Alameda, where sandy soil sometimes drains too quickly and lets nutrients wash away. Cover crops can also attract beneficial insects and keep down weeds.

Cover crops come in two basic types:

  1. Legumes, like bell beans and peas, add nitrogen to the soil and attract good insects.
  2. Cereals, like triticale, oats and barley, build organic matter. Mix the two types to get both benefits. Seed mixes are commercially available.

Cover crop seeds aren’t found everywhere, so call around to local independent nurseries or go online.

Try to plant cover crops by the end of October, and follow the directions on the seed packet. Legume cover crops may work better with the addition of an inoculant. Simply put, inoculants are bacteria that cause the legume plants to form nitrogen-fixing nodules. Follow the directions on the inoculant package. Some irrigation will be needed until the rains come.

Come spring, there should be a nice stand of greens. Now there are two options:

  1. Chop the greens down, pull up their big roots, cut everything into small pieces, dig it all into the soil and let the whole thing rest until the greens rot into the soil. This will require waiting three to six weeks before planting a spring crop. If planting before that, the nitrogen won’t be as readily available for the new plants.
  2. Wait until the greens are knee high, then cut them down to ankle height and place the greens in a compost bin. Do this more than once over the winter if possible. Then, when ready to plant, pull up the big tap roots and remaining greens. Plant the spring or summer food crop where the cover crop was. Add the compost around and under the new plants.

In the summer, the plants will be grateful for the added nutrients provided with “green manures.”

Alameda Backyard Growers will be submitting a regular gardening column for the Alameda Sun. Click here to read the original article in the Sun.