Common Name: butterfly bush
Type: Broadleaf evergreen
Family: Lamiaceae
Zone: 9 to 11
Height: 2.00 to 4.00 feet
Spread: 2.00 to 3.00 feet
Bloom Time: Seasonal bloomer
Bloom Description: Light blue/violet (bicolor)
Sun: Full sun to part shade
Water: Medium
Maintenance: Low
Flower: Showy
Leaf: Evergreen
Culture
Easily grown in organically rich, evenly moist, well-drained soils in full sun to part shade. Best performance occurs in part shade. Plants require regular and consistent moisture. Winter hardy to USDA Zones 9b-11. Best in frost-free climates. Plants may freeze to the ground in zones 8-9 when temperatures dip below 25 degrees F., but roots may survive and send up new stems in spring as if it were an herbaceous perennial. Regardless of winter temperatures, prune stems hard to the ground in early spring if compact plant form is desired. Propagate by root suckers, cuttings or root sections.
In St. Louis, blue butterfly bush may be grown in patio containers which are overwintered indoors in bright conservatory-like rooms in indirect sun. Mist foliage frequently.
Noteworthy Characteristics
Rotheca myricoides, commonly called blue glory bower or blue butterfly bush, is a suckering evergreen shrub with a somewhat open habit which grows rapidly to 6-10' tall and as wide in its native habitat but more typically to 2-4’ tall in containers in the St. Louis area. It is native to tropical eastern Africa (Kenya and Uganda). This shrub was formerly known as Clerodendrum myricoides. Glabrous, elliptic to narrow-obovate, glossy bright green leaves (to 3-5” long and 1-3” wide) have serrate margins and wedge-shaped bases. Showy, five-petaled flowers bloom June to September. Flowers purportedly resemble the shape of a butterfly in flight, hence the common name of blue butterfly bush. Variable flower color ranges from blue to violet blue to white. Each flower has four light blue side petals (resembling butterfly wings), a fifth dark blue lower petal (resembling butterfly head, thorax and abdomen), and showy, curved, outward-arching, purple stamens (resembling butterfly antennae). Black fleshy fruit follows the spring blooms.
Genus name is reportedly a Latinization of the Malaysian words cheriga meaning small and thekku meaning teak.
Specific epithet comes from the French word myriades meaning ten thousand and a Latinization of the Greek –oides meaning to see.
‘Ugandense’ is a cultivar that features intense purplish-blue flowers with showy stamens. This cultivar was originally named Clerodendrum ugandense, but was later changed to Clerodendrum myricoides ‘Ugandense’. DNA studies from 1998 led to a further change to its current listing as Rotheca myricoides ‘Ugandense’.
Problems
No serious insect or disease problems. Watch for aphids, whitefly, mealybugs, scale and spider mites. Leaf spot is an occasional problem.
Uses
Attractive flowering shrub. Containers.