Disturbed, open sites of grasslands, pastures, and agricultural lands, especially grain fields. Inhabits many soil types. Northwestern and Central-western regions, central Sierra Nevada. Seed heads can disperse by animals or machinery. Seeds often mature with a high rate of dormancy.
Dormant seeds appear to require leaching of germination inhibitors and light to break dormancy.
Rates of dormancy can vary among populations at different locations. Most seeds germinate after the first fall rains 1-3 years following maturation, but some seed can remain dormant and viable for up to 8 years under field conditions. Germination of seeds at locations with low rainfall and temperatures can be slow and drawn out. Typically, few seeds germinate after midwinter. Seedlings rarely emerge from soil depths below 5 cm.