Winter rye grass is best planted in the fall, between August and October. The colder the climate, the sooner the grass should be planted. The ideal temperature for growing winter rye grass is 50 to 65 degrees Fahrenheit.
Winter rye is a fast-growing cereal grain. Used as a cover crop, the grass prevents soil erosion and inhibits weed growth. The grass has a deep root system, which draws minerals from deeper within the soil upward to the surface soil. These nutrients are stored within the blades of the grass; when tilled in the spring, the grass releases the nutrients back into the soil. Trimmed winter rye also works as mulch for the garden in the spring.