If you are lucky enough to have farms in your area you might have noticed that at the end of Summer and early in Fall after they have harvested their main crop they plant a crop of winter wheat or something else that is often called a cover crop.
The reason behind planting a cover crop is to control weeds and to provide an organic material that can easily be turned into the soil next spring to add natural nitrogen. It also protects the soil from erosion which may be of more importance to large farms but will keep your garden soil nutrients in the beds and not washed away by late season hurricanes.
Weed control is something that you must take care of late into fall as weeds often grow much faster than other plants. They are also the most active in spring and to help yourself it is a good idea to plant a throw away crop that can displace weeds in the garden. This crop may be turned under to provide organic material and nitrogen but the primary idea is that if a friendly plant is growing someplace a weed has a harder time growing there.
Many farmers use a winter wheat for cover crops but in a home garden this is not something that you really want to do. Winter Wheat is something that is easy to deal with when you have large machinery but for the small home gardener it is like you are planting grass in your garden and this can almost be as bad as weeds. I would only suggest it if you have a very large area and use a large rototiller or small tractor to prepare your soil. If you have a smaller garden you can still benefit from a winter cover crop by planting seed that you have left over from past seasons.
Some plants actually add nitrogen to the soil where others use the nitrogen in the soil. If you are planting a winter cover crop you want to pick something that has a weak root system which will be easy to turn over in the spring but will block sun and weed growth.
Plants that are low to the ground provide the best protection from rain and erosion.
Normally I like to plant something like collard greens because they are hearty late into the fall and if you are lucky enough to be left alone by grasshoppers and beatles you can harvest some of it for your kitchen table. I have looked out my back window and seen collards surviving even after the first light snow. I probably wouldn’t eat them at that time of year but if worst came to worst I guess it would be possible as long as they don’t show physical damage or disease.
I would not suggest that you plant something like tomatoes or squash but pretty much you can plant anything.
If you are having blight in your garden then I would not suggest a cover crop. Any type of bacterial infections or other diseases such as fungus you want to rid from your garden before the next season.
Also it is very important that if you are having problems with tomato blight that you remove all of the plants from your garden and do not turn under any tomatoes or plants. You will only spread the problem.
If your garden is very small say 10 feet x 10 feet you can pass on the idea of a cover crop and simply cover the soil with heavy black plastic that will block all light and stop weed growth.
So if you have some time left in the season and you have some extra seed try growing a cover crop of collards or radishes or something easy to deal with. It may save you work next spring or it may put a couple more meals on your table before winter comes.