Cover crops can be an elusive subject for someone who hasn’t grown them before. When folks usually think of having a vegetable garden, they often consider only the vegetable plants. However, those plants need to be fed and if they are grown in the same space year after year with nothing added for nutrition, the productivity of your garden and the health of your soil will decline.
Bringing inputs from somewhere else to feed your garden brings up the sustainability concern of the depletion of the resources at somewhere else. If your compost depends on the manure and bedding from your neighbor’s horse, then you have to consider where the feed and bedding materials for that horse came from and how the earth is compensated for that. If amendments were brought in to fertilize the grain/straw/hay used by the horse, it broadens, even further, the footprint that is required to feed your garden, and ultimately you. It is good to have your soil tested and add minerals and anything else that may be necessary, using organic amendments. You will also need to add organic matter. Continuous additions of organic matter are needed for all gardens, especially if you have sandy soil or clay soil. Organic matter serves as a slow-release fertilizer that helps build soil structure and is home to microbes, keeping your soil alive. To build organic matter in your soil, think cover crops.
You could address your organic matter needs by bringing in mulch in the form of leaves or straw or buying compost, but then you would have to contend with the ever-widening footprint of your garden. Besides that, there is the possibility of Killer Compost, which I wrote about here. Even if you were okay with that, you have to acquire those things, then haul them around. However, you can grow all your mulch and compost materials right in your garden! When you do that you have the added benefit of the organic matter and soil life that results from the roots of those crops. It is hard to explain just how much those roots that are left in the soil add to your garden. You may have to see it and touch it to believe it, but it is amazing! Picture the crop above ground; then picture that much biomass as roots that are added to your organic matter reservoir. A wonderful bonus is that you don’t have to haul it there.
You don’t need a tiller to manage cover crops. In fact, to get the most benefit from these crops, using a tiller would be a disadvantage. I propose to let the cover crops grow to maturity, or almost to maturity (flowering stage) and cut them with a sickle. You can let them lie where they are as mulch for the next crop or use the biomass as material for your compost pile. It is possible to plan enough cover/compost crops to make all the compost you need. More on that here. To manage these crops without a tiller you need to plan carefully. It is not quite so important with the legumes, such as peas, beans, and clovers. They can easily be pulled out or cut with a sickle and put in your compost pile. Unless you need the area sooner, wait until the plants are in full flower before you cut them.
The grain crops, such as rye and wheat, are different. Their root systems are so extensive that, if you cut the plants at full flower (you wll see they are shedding pollen), the plants won’t regrow, but you will still have a lot of roots to deal with. Wait two weeks for the roots to begin to decompose before you transplant into that bed. If you want to plant seeds after a cover crop, rather than transplants, use a legume as the preceding cover crop or wait until the grain crop has fully matured to cut it. At that point you will have seeds and straw. The plants will have completed their life cycle and the roots are ready to expire into the soil. Without removing the stubble, you can use a hoe to make furrows and plant seeds.
Cereal rye, also known as winter rye, gives me more biomass than wheat. I like to use it before crops, such as corn, tomatoes, and squash that I want to mulch. I’ll cut it and let it lie right there in the bed. This mulch will eventually break down, feeding the soil, but by then I will have a crop that is spreading over it to cover the soil. Sweet potatoes do this nicely beneath my corn. Legumes have less carbon, causing them to decompose much faster than straw from the grain. You could cut it and let it lie as a mulch, but you better have a plan to add more mulch soon, or you will be left with bare soil and Mother Nature will plant her weeds there.
I plan for at least 60% of my garden for the year to be in cover/compost crops so that I have enough biomass for the compost that I need. It is not all rye and clover. Some of the compost material is corn stalks, which provide much needed carbon in my compost pile. I designate a bed for my compost piles for the year, rotating it to the next bed in October. The goodness that has leached out of the compost all year is taken up by the cover crop, usually rye, which is planted in the former compost bed. The rye soaks up the goodness left by the compost and gives it back to the corn crop the next year when I cut the rye at pollen shed and leave it in place as mulch for the corn. Rye cut at flowering (pollen shed) in early May stays in place as mulch. Rye cut when the seeds are mature in mid-June goes to the compost pile as straw. The seeds are saved for eating or planting in the fall.
The bulk of your cover crops will be planted in the fall, but I am writing this now so you put them in the plan you are making for this year’s garden. Make a garden map and fill in each bed with everything that will grow there for the entire year—all 12 months. Add appropriate cover crops that will be out in time for the next desired crops to go in.
So much to tell and so little space……. You will find more information throughout my blog and in my DVDs and my book Grow a Sustainable Diet. Once you have some experience with cover crops, you will realize that it is the easy way to go.