Kalm's St. John's Wort - Hypericum kalmianum

Features: In mid summer, beautiful yellow flowers cover this shrub, which keeps its foliage a long time and can be used as a hedge and will provide winter interest. It gets its common name from blooming around June 24th, the feast of St. John the Baptist, though that varies with local conditions. Very popular with bumble bees. 

Light: Full sun to part shade

Soil: Does well in clay if it gets sun

Height: 2-4 feet

Blooms: July to August

See more information and photos at: Missouri Botanical Garden and USDA Plants Database

Photos: 1 Possibility Place, 2-4 Illinois Wildflowers