Bougainvilleas (Bougainvillea species) are tropical and subtropical woody vines of the Four-O’Clock family (Nyctaginaceae). They are named for Admiral Louis A. de Bougainville, a French explorer (1729-1811) who discovered them in South America. They are thorny, evergreen, and are popular for their large, colorful “blooms,” which are produced most profusely in summer. Like the dogwood and the poinsettia, their colorful “petals” or “flowers” are really modified leaves called bracts that surround the true small white tubular flowers. They may range in color from white, yellow, orange, pink, purple or crimson.
The genus Bougainvillea contains several species. Only three (B. spectabilis, B. glabra and B. peruviana) are important horticulturally. Many crosses among the various species of bougainvillea have produced new hybrid species and important horticultural cultivars. Some hybrids names are ‘Don Mario®,’ ‘Gold Rush®,’ ‘Jamaica White™,’ ‘Orange King,’ ‘Raspberry Ice,’ and ‘Scarlett O’Hara.’
Bougainvilleas are vigorous and respond well to pruning and as a result they often are utilized as hedges in more tropical areas. They are extremely drought-resistant and thrive in almost any soil type that does not stay constantly wet. They thrive in USDA Zone 10, but will survive in Zone 9 if protected. In most of South Carolina (Zones 7 and 8), they can be grown as houseplants, in greenhouses and as container plants. They can also be grown in the landscape if treated as an annual.
Outdoors, bougainvilleas should be in full sun (no shade) and in a well-drained soil with a pH of just over 6.0. They should be fertilized at half the recommended rate once a month with a general-purpose fertilizer (e.g., 10-10-10) in early spring and midsummer. Prune suckers from the plant’s base to encourage top growth. Severe pruning should be done after summer flowering (i.e., in late fall or very early spring). Stem cuttings from current year’s growth can be propagated (rooted) in a sand/peat mix during summer. Dead wood should be removed as it appears.
In general, bougainvilleas will flower sooner and more profusely if exposed to high light intensities, moderate temperatures and longer nights. These conditions are common in very early spring. Bougainvilleas will eventually flower under the shorter nights of summer but will produce more leaves before they initiate flowers.
Bougainvilleas may be affected by fungal and bacterial leaf spot diseases. Their insect pests include aphids, scales and mealybugs (in the greenhouse). For more information on diseases & insect related pest see HGIC 2251, Houseplant Diseases & Disorders & HGIC 2252, Common Houseplant Insects & Related Pests.