Seed is often a contaminant in hay, grain, and straw and is difficult to separate from crop seed. Germination is increased by moistening of stratum. Litter also promotes germination and establishment of seedlings. Seeds will germinate regardless of whether they are in contact with soil. However, germination is enhanced when in contact with soil.
Seeds germinate best in dark or diffuse light.
Adequate fall or spring moisture seems to be primary factor which inhibits germination. Competition Competes for soil moisture with perennial grasses because of its early spring growth habit. An excellent competitor for soil moisture and is capable of reducing soil moisture levels to permanent wilting point in upper soil layers. Capable of invading perennial bunchgrass communities that have been protected from grazing and fire in the Columbia Basin. Although a competitive plant, generally does not tolerate shading.