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Summer cover crops

When you harvest a crop early in the season (for example, radish, peas), you have an opportunity to follow it with a warm season cover crop. Also, many experienced organic growers keep a supply of cover crop seed on hand to provide a quick cover when they experience the inevitable occasional crop failure. Species commonly used for summer cover in the Northeast include oat, buckwheat and sudex (sorghum-sudangrass hybrid. These are all relatively inexpensive, and often can be obtained locally. Cowpeas (black eyed peas) can be planted to provide nitrogen for a succeeding crop. All of these species have relatively large seeds that should be worked into the soil with a rake or hoe to insure successful establishment. If the weather is hot or dry, irrigation will speed establishment and improve density.

Working the seeds into the ground will simultaneously remove any small weeds that have established in the previous crop. Large weeds should be pulled or dug out prior to sowing the cover crop. A dense sowing of a warm season cover crop will smother most species of annual weeds, and also add organic matter to the soil. A summer cover crop should be cut or incorporated before it goes to seed to keep it from sprouting up and competing with crops next year. Also, be wary of small weeds that may persist in a suppressed state while the cover crop is in place and then set seed after it is cut. Often the best strategy is to shallowly incorporate the summer cover crop in late summer and then plant a winter cover crop.

If a crop will not be planted until mid summer and no winter cover crop was planted the previous year, you can use a spring sown cover crop to protect the soil, suppress weeds and add organic matter to the soil. Oat, grain rye and field pea are all used for this purpose in the Northeast. For more information on cover crops, see Resources.