Rehmannia produces flowers continuously over a long period of time from spring to fall. In places with really hot summers, Rehmannia may rest for a while during the dog days and resume flowering when cooler temperatures arrive.
More Information About Rehmannia
Rehmannia is a small genus of 6 species from China that are related to antirrhinum (snapdragon) and buddleia. The common name "Chinese foxglove" gives you a good picture of what the flowers look like.
Rehmannia is a deciduous herbaceous perennial with a basal tuft of leaves and a 2-3' tall central flower stalk. Lining the flower stalks are foxglove-like, trumpet-shaped flowers that are generally pink with a red-spotted, yellow throat. Rehmannia produces flowers continuously over a long period of time from spring to fall. In places with really hot summers, it may rest for a while during the dog days and resume flowering when cooler temperatures arrive.
Rehmania (Chinese Foxglove) Growing Conditions
Rehmannia plants can tolerate a wide variety of conditions, from moist to dry, and full sun to part shade but they perform best with consistent moisture and well-drained soil. It also prefers recently loosened soils as they tend to decline in soils that have not been disturbed. Chinese foxglove is a great pass-along plant because it spreads easily on rhizomes to form a colony that can be divided and shared with your friends.