Cover crops are usually grown in the off-season to provide benefits to the subsequent cash crop. In North Carolina, summer cover crops can be planted in the production window immediately following spring harvest and prior to fall planting of vegetable crops. The best use of cover crops maximizes the benefits described above without reducing the yield or quality of commercial cash crops. A combination of two or more types of cover crops may be beneficial for quick establishment and improved nutrient utilization. Seed cost, method of seeding, and method of killing the cover crop should also be considered. There is growing interest in the use of short-season summer annual legumes or grasses as cover crops and green manures in vegetable production systems. Legumes cover crops such as clovers, hairy vetch, field pea, annual medic, alfalfa and soybean fix atmospheric nitrogen into a form plants and microorganisms can use.