There are a multitude of reasons to plant cover crops. They range from wanting to add green manure (nitrogen) to the soil to resting the gardener. Planting crops that have a nitrogen fixing ability will yield green manure in the spring. Some of the most common are peas, beans, clovers and vetches. To get the most from these crops you must inoculate the seeds prior to planting. Inoculants are specific to the type of seed, so make sure you get the correct one and follow the directions. Any excess inoculant you have should be added to the garden soil. Do not let these crops flower.
Cereal grains such as wheat, oats, rye grass and cereal type rye are cover crops that do not require inoculants. They have some nitrogen fixing ability and will help with soil compaction, weed suppression and add a tremendous amount of organic material back into the garden in the spring. Cereal type rye will also trap root nematodes.
Planting rates for these crops vary quite a bit so know how many square feet you are wanting to plant. The seeds of all cover crops should be buried when planted. When spring comes there are two ways to handle the cover crop. One method is to cut the cover crop and then plant the veggies. It works but this puts the two crops in competition for the same resources. The other method is to kill the cover crop with an appropriate herbicide at the recommended rate. Or, (my favorite) about a month before you turn your garden, cut back all cover crops to about six inches tall then deeply turn (or till) the entire area into the soil. If you planted a cereal crop, make sure you add some nitrogen (fertilizer) to the soil. Molasses will also work but takes longer than a fertilizer. For those that planted cereal rye for nematode control, you should remove and dispose of the crop. Click here to read more about Cover and Green Manure Crops.
