Oats should be planted by early September in the Puget Sound area to get good fall growth. Later planting is unlikely to produce good ground cover. Planting can be as late as October in the Willamette Valley. Oats tolerate wet and heavy soils better than other cover crops, but oats are susceptible to early winterkill. Winterkill is less of a problem in the Willamette Valley.
Spring barley is an early cover crop that is similar to oats in growth characteristics.
It is also susceptible to disease and occasional winterkill. Barley produces a large amount of leaves, but most of its growth comes late in the spring. Winter barley is also available, but is only slightly more winter hardy than spring barley. Triticale grows similarly to cereal rye but produces more vegetation. It is a leafier plant than rye and may decompose more easily when turned under.