November 16, 2010

Grasses and legumes usually are planted in early spring at the onset of your busy season; however, planting now after harvest, during the dormant season, can be nearly as successful.

Dormant plantings succeed as long as soil is relatively dry and soil temperature is too cold for seeds to germinate. That's the main key — too cold to germinate. When these conditions exist, seed just lies in the soil until conditions favorable for germination occur next spring. Then seeds begin to grow as if they had just been planted.

Warm-season grasses, like those used in CRP and range plantings, are especially well-suited to dormant planting. They won't germinate until soil temperature exceeds 45°F. Since soils generally remain colder than this for most of the winter, dormant plantings of these grasses can be made anytime between late November and March. In addition, the alternate warming and cooling of the soil in spring stimulates a natural process in these seeds that improves their germination.

Cool-season grasses and legumes, however, can germinate at soil temperatures as low as 35°F. Our soils often are warmer than 35°F for several days in a row during winter, so cool-season grass seeds occasionally germinate and then die when soils freeze again. As a result, dormant plantings of cool-season species are successful a little less often than warm-season grasses.

Bruce Anderson
Extension Forage Specialist