Though the plant looks like a tall weed, this pretty flower is blooming now in fields and open areas.
As its name suggest, Biennial gaura (Gaura biennis) takes two years to bloom. In the first year it's a rosette of basal leaves that sends down deep roots to survive wet winters and dry summers. In the second year it grows 4-6 feet tall and blooms in August.
The flowers are white when they bloom and turn pink as they fade. I never notice the plant until the flowers are pink.
(photo by Kate St. John)