Improve Garden Soil with Cover Crops

It is important to add organic matter to your soil every year – whether you’re using chemical fertilizers or gardening organically. Healthy soil is alive, actually teeming with earthworms and micro-organisms by the millions that have each got particular functions in making the soil fertile.  If your garden soil is going to continue to produce for you, it needs to be fed plenty of organic material.

Soil life eats and decomposes organic matter, which causes minerals to be released in a form that plant roots can absorb.  In addition to this fertilizing effect, all the organic waste helps the texture of the soil – loosening hard-packed clay or binding loose, sandy soil.  Humus gives the soil its necessary sponge-like texture that allows air circulation and moisture retention.

For these natural processes to occur, the soil life needs fresh supplies of food.  Without this fuel, earthworms go away and the minerals and nutrients get ‘locked’ in soil particles, not available for plant growth. Insect pests and diseases take over the weakened plants.  Pouring on the chemical fertilizers won’t help because they don’t contribute to soil texture and flourishing soil life.

This is a simplification of a very complex natural process of soil chemistry that justifies in-depth study in its own. But the intention here is to give a basic idea of the absolute necessity of a generous annual addition of organic matter to all continuously used garden soil.  Now, here are some suggestions about how to feed the soil.

One method, of course, is to chop garden residues and weeds into the soil after a crop is harvested. Also, there’s the option to haul in compost, in packages or in bulk when available.  If there are processors in your area, (such as canneries or cider mills), often they will have waste organic material for the taking.  Nearby farms usually welcome removal of animal manures: cattle, horses, chickens and rabbits. Any hay or straw used as mulch can be chopped in, along with leaves and lawn clippings.

The fastest and easiest way to turn almost any bit of soil into superior loam is to use cover crops, also known as green manures, and till them in.  Over time, this practice will add to the topsoil rather than take it away with harvested crops.  This is especially necessary for the gardener who is growing food in the long-term on the same patch of ground.

Some Gardening Notes:

1. Green manures can be grown in rotation: follow an early cover-crop with a late-season planting of produce, or a plant late green manure following an early vegetable crop like peas and lettuce).  That way even small gardens can have a harvest crop and a cover-crop each year.
2. Using green manures can be done by any gardener with or without powered equipment.  However, a roto-tiller is the easiest method.  If necessary, you can rent one. Here are some suggestions for home garden cover-crops.
   1. A) Use legumes such as soybeans, peas, vetch, and alfalfa. They will ‘fix’ nitrogen from the atmosphere when you use ‘inoculated’ seeds that are attractive to a certain kind of microbe.  Also, some legumes are vegetables, providing both food and a green manure with the same crop.
   2. B) Plant ryegrass for a bulky, hardy crop that grows quickly. An annual variety is best, so that a late-summer crop will die back during winter allowing easy tillage in spring.
   3. C) For extremely poor soil, buckwheat is recommended.  It will grow quickly and choke out weeds as well.  Sow buckwheat for the main summer crop, after harvesting lettuce, etc.

The benefits to the soil of using cover-crops can’t be overstated.  In addition, there are other advantages: they help control weeds, they attract bees, and the carpet of green makes the garden look good right up to snowfall.