Cover crops are typically planted just after the last summer or fall harvest and are meant to cover the soil throughout fall, winter and early spring.
Cover crops have numerous benefits, including protecting against erosion and improving soil structure. They also boost soil fertility, nutrient content, and earthworm/microbial activity by adding organic matter to the soil.
https://www.almanac.com/planting-cover-crops-home-garden
Common cover crops include grasses and legumes like winter rye, hairy vetch, red clover, oats, buckwheat, forage rye, Italian ryegrass, field beans, and forage peas
Most cover crops can be tilled right into the soil a few days before spring planting. Watch this video for other ideas on how to get rid of cover crops after their job is done.