There are over 400 species of clerodendrum native to tropical and subtropical Asia and Africa. They can be deciduous or evergreen and vary from herbaceous plants to trees. Clerodendrums are grown for their exotic-looking flowers, and some are vigorous enough to become invasive. Some species will survive temperatures down to zero degrees Fahrenheit, while others are killed by frost.
Plant your clerodendrum in a partially shaded site with some direct morning or late afternoon sunshine. Choose a site with fertile, well-drained soil. Provide vining species with a support trellis or other structure to clamber over.
Water your clerodendrum generously in the summer months and do not allow it to dry out. Reduce watering during cooler spells and in the winter.
Fertilise clerodendrums every month with a micronutrient-enriched liquid fertiliser or apply a slow-release granular fertiliser every 2 months. Reduce fertilisation after the flowering period is over.
Prune your clerodendrum in late winter before new growth begins to appear. Cut back all the stems on your plant, as the season's flowers will grow on new shoots.
Take 2- to 4-inch cuttings of fresh, spring shoots and plant them in well-drained compost. Place in a humid spot with bright, indirect light and keep the compost moist.
Grow the frost-tender blue butterfly bush (C. ugandense) in areas with minimum temperatures of -12.2 degrees C. This East African species is grown for its 10-inch-long clusters of blue flowers, which appear throughout the summer and early fall.
Plant the bleeding heart or glorybower (Clerodendrum thomsoniae) in gardens with minimum temperatures of 7.22 degrees C. This vining clerodendrum produces 4-inch clusters of red or red-and-white flowers.
Grow the West African flaming glorybower (C. splendens) in frost-free gardens. It thrives in full sun with some shade during summer afternoons.
Plant the cashmere bouquet (Clerodendrum bungei) in areas with minimum temperatures of below zero degrees F. It produces clusters of pink flowers and can be grown as a shrub if heavily pruned every year.
Ask about the exact growing requirements of the clerodendrum species you choose at point of sale. Grow frost-tender species in large pots and move them indoors for the winter.