Improve Your Garden Soil with Cover Crops

Originally Posted on September 14, 2013

“Globalized industrialized food is not cheap: it is too costly for the Earth, for the farmers, for our health.” ― Vandana Shiva

Greetings Farmers and Gardeners,

We are half way through September, and quickly approaching the official beginning of autumn. It is a great time to sow cool-season cover crops in beds that have been cleared of crops. Cover crops help add green manure to the garden, prevent erosion, and improve tilth to the soil.

We are still harvesting tomatoes from our trial garden at Valley Oak Tool HQ. David has the great tomato hedges he promised, and Carla's plants are sprawling this way and that. David is still watering frequently, whereas Carla has not watered her plants in more than a month, and the plants are healthy, so the deep mulch is doing its work to keep moisture in the soil. David's hedge of tomatoes is much easier to harvest than are Carla's sprawling plants. We are enjoying watching the experiment of the tomato garden.

Improve Your Garden Soil with Cover Crops

Sowing seeds of cool weather cover crops in the fall is an excellent way to build your soil. During the winter a fall-sown cover crop will help hold the soil during winter rains (providing protection from erosion), help keep nutrients from leaching away, and add organic matter to the soil. The roots of a cover crop help keep an active exchange with soil microorganisms. Cover crops are also beneficial in keeping weeds from taking over bare soil. A cover crop can be selected to reduce nutrient deficits, break up hard soil, and create large amounts of organic matter.

Daikon radish is an excellent crop for drawing minerals from deep sources. The root of the daikon can grow to six feet deep or more in the fall. The large root that grows is a benefit for those with compacted or clay-heavy soil, as the root will help to open the soil to assist in water penetration. We like to use daikon in a spot where we will be planting in the summer, and we just wheel hoe the tops off in the spring, leaving the roots to decompose in the soil. If we want to use those beds in the spring, we'll use the broadfork to "harvest" the crop, which we then add to the compost pile, to be added as a side-dressing later in the season.

Leguminous crops - clovers, fava beans, vetches

Members of the bean and pea family are a good choice as cover crops if you wish to add nitrogen to the soil. These plants take nitrogen from the air and grow nodules of nitrogen on their roots. When the tops of these plants are cut (around flowering time, before seed set) the nitrogen will be released into the soil, making it available to soil organism, and other plants.

Fava beans are a favorite around here because of the beautiful, large stand of green they make, and the lovely white flowers. The green tops can be cut down with our wheel hoe (with a sharpened blade) and incorporated into the soil or composted. Leaving the roots to decompose in the soil will allow the nitrogen to be released to the soil organisms. Most annual cover crops from the legume family make large amounts of organic matter.

Fall Rye is also a good cover crop that will either winter-kill or grow slowly during the cold weather. Rye and other cereal cover crops help prevent compaction and improve soil tilth. When shown in in the fall, the rye will put on enough growth to help prevent erosion during winter rains. Rye (and other grasses) have an allelopathic effect, which helps keep weed seeds from germinating and growing. In the spring the soft, green rye can be dug into the soil, allowing it to decompose for several weeks before planting new crops. If you leave the rye to grown tall and woody, it can be cut and composted, or cut and used as a mulch.

Peaceful Valley Farm Supply has an excellent selection of cover crop seed, and a considerable amount of information available on their website.

Whichever cover crop you choose, you can rest assured you'll be doing your soil a great service by planting one.

Saving Seeds of Cucumber

Leaving a few cucumbers on the vine, well beyond the ideal time to harvest for eating, will give the seeds time to mature. You'll need mature seeds if you want to save them for growing next year. A mature cucumber appears to be an alien when compared with the tender, young cucumbers we harvest for eating. One of our gardeners has been growing lemon cucumbers from her own saved seed for several years. Mature lemon cucumbers look like a small balloon stretched to near-bursting.

When cucumbers have reached full maturity for seed saving, they will be quite large, and a little soft. According to Suzanne Ashworth's book Seed to Seed, fruits that are kept for a couple of weeks after being cut will produce more seeds that are viable.

Ashworth recommends using a short fermentation process on the seeds, letting them sit in a warm place, in water equal to the amounts of seeds. Keep the fermenting seeds out of the sun, and be prepared for unpleasant smells coming from the container of fermenting seeds (best to keep it outside, under cover).

Once fermentation is complete, add more water and stir up the mixture. This will allow the good seeds to sink to the bottom and you can pour off the floating seeds and other debris. Once the seeds are thoroughly cleaned, strain them and dry them on a non-stick surface, such as a ceramic plate, or cookie sheet. Do not dry them on paper towels or on cloth, as the seeds will stick to those surfaces.

Until next time, we wish you a great fall gardening and farming season!

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