It is vigorous, very cold hardy, and can germinate and become established in cool weather. When planted by early September, rye will capture some of the available nitrogen in the soil and recycle it for the next crop. Rye grows rapidly in the spring and can become difficult to turn under by the time gardeners are ready to work their gardens. Mowing may be necessary before turning under heavy growth of rye. Rye may suppress the growth of spring crops, but this is likely to happen only when heavy growth is turned under and not allowed to decompose before spring planting.
Winter wheat is most suitable for mid to late season plantings.
Plantings before late September are susceptible to disease and premature death. Winter wheat covers the ground quickly in the fall, but does not grow as vigorously as rye does in the early spring, making it a good choice for late planted gardens. Wheat is more leafy than rye, so it may decompose faster when it is turned into the soil. Spring oats are a good choice for an early cover crop, as they grow vigorously when the soil is warm. Oats should be planted by early September in the Puget Sound area to get good fall growth.