Perennial. White, pink or purple flowers appear in Summer. 
To germinate, needs 30 days cold, moist stratification. Best late Fall or Winter sown. 
Full to partial sun.
Moist to dry soil. 
Grows 3' - 4' when fully mature. 
Space plants 2 to 3 feet apart. 
USDA zones 3 to 8
Host plant for monarch butterfly larvae.