GARDENS FOR HUMANITY: Cover crops feed our soil twice, and us too
Bare soil starves for plants. That is why disturbed or bare soil invites weeds. Weeds! These unappreciated guests do the important work of restoring and nourishing the earth.
Weeds inject nutrients into soil through photosynthesis − proteins, carbon, nitrogen, sugars and vitamins. Their roots carry food, create pathways for water penetration, and break up compacted soil. They are also the hosts for fungi and microorganisms − all soil builders. The leaves shade the ground, reducing evaporation. When the weeds die, they provide organic matter, further feeding the soil while aiding water retention. In nature, “weeds” are the first plants in the process of plant succession, turning dirt into soil that is hospitable for other plants.
Many of the “weeds” are the wild members in families of other useful plants, such as grasses, clovers, sunflowers, brassicas (mustard and cabbage family), nightshades, mints and sages, chicories, and amaranths. Their domesticated cousins are often welcome foods and herbs in our garden. Because weeds are wild and opportunistic, they have survival properties, such as abundant spreading seeds or runners that we don’t appreciate and that make them invasive. Many of these “weeds” have medicinal or nutritious properties that have resulted in their domestication for millennia, and include most of our common foods and herbs.
Effective gardening imitates nature. In the yearly cycle of seasons we can pace our activities accordingly. Even during winter in our region, the soil is not sleeping. With the visible cold-tolerant plants above ground, we have many beneficial lives below ground that make our soil fertile. Instead of adding artificial fertilizers, we can introduce cover crops, some of which are also edible. These domestic versions of weeds, do the work of nourishing and building soil.
When warm weather crops are finished, we can replace them with cover crops that improve soil nutrients and health. When the cover crop is finished, the tops can be turned into the soil, or used for compost or mulch. These continue to feed and enrich your soil as you prepare for the warm planting season. Soil is a living organism that we also nurture by using it to grow plants − even when our active gardening season is over.
In our garden, we plant cover crops in early fall. These contribute to soil vitality and most of the plants we eat. Our winter salad is made up of the leaves of cover crops such as mustard, arugula, endives, winter peas, fava beans, and lettuces. In the spring these plants provide flowers for nectar and pollen for bees, and seeds that we also eat (peas and fava beans). Peas and beans are nitrogen fixers, and all have deep root systems. We have also planted grains in our garden as a winter crop, and garlic and onions are winter staples. Brassicas (kale, collards, cabbages of all kinds), spinach, lettuces, parsley, chard, cilantro, and many root vegetables thrive in winter.
Although it is late for planting a fall-winter garden, it is a great time to plan for the coming gardening year. The planting guide available on the home page of the Gardens for Humanity website, www.gardensforhumanity.org, is a useful resource for planning. Cover crops can be planted at any time during our planting season from February through October to improve soil fertility.
Richard Sidy is president of Gardens for Humanity, a founding member of the Sustainability Alliance and a member of the Verde Valley Food Policy Council. To reach him, email president@ gardensforhumanity.org .