Common Oats (Avena sativa) Oats have been grown as a cover crop for decades. Oats are a cool season annual grass that grows well during the fall and can tolerate heavier soils that may become saturated. Plants grow up to four feet in height. Benefits of sowing oats include: forage, weed suppression, nutrient removal, erosion control and soil softening. We use oats as a cover crop to limit erosive tendencies on our sandy-loam soils, particularly in the late fall. Also, the straw residue is great for winter mulching on our root crops such as garlic and other biennials. Approximately 400 seeds per packet sows a 4 x 8 foot raised bed or similar sized garden plot.