Great St. John's wort flowers are the largest Hypericum flowers to be found in Missouri and can measure 3 inches across. Unfortunately, they only bloom for a couple of weeks; but that is plenty of time for bumblebees and other insects to stop by for a visit. The flowers are soon replaced by large, interesting seed pods that change from bright green to dark brown as they ripen. It has a rhizomatous root system and can spread underground to form small colonies. Though it is easy to grow, this is an uncommon plant in Missouri and large natural populations are seldom seen.
Uses: Butterflies, medicinal
Bloom time: June - August
Height: 2.5 to 6 feet
Space: 1.5 to 2 feet
Sun: Full sun to light shade
Moisture: Average to moist