There are many places online (and in books) where you can read about crop rotation in depth, the whys and wherefores.
Black Crowder Peas are an excellent summer cover crop.
One thing to note is that the bean family can be used as a cover crop anywhere in the rotation when wanted or needed.
SUMMER: southern peas in the summer are a very effective cover crop, shading out weeds (if you start out with a weed-free bed) and potentially enriching the soil. They require a week or two’s attention at seeding time (late May or June) to get them established (regular watering til the seedlings are established), then they are fairly drought-free, requiring water when it stays very hot and dry for an extended period of time. Several beds at the WCG were successfully cover-cropped last summer with the Black Crowders (a southern pea).
WINTER: Elbon cereal rye is usually grown as a winter cover crop, as it is a root-knot nematode trap-crop. One of the WCG gardeners has been successfully growing fava beans as a winter crop. They are beautiful and just beginning to flower now.
Wishing our gardeners a bountiful vegetable and herb harvest this year!