Known for its stunning flowers and rapid growth rate, bougainvillea (Bougainvillea spp.) is widely available, inexpensive and easy to grow. Depending on the species, vining bougainvilleas can reach 30 feet or more in height. The versatile bougainvillea comes in a profusion of colors, and the many varieties differ in size, growth habit and tendency to bloom.
Diverse Bougainvillea Types
The garden favorite, great bougainvillea (Bougainvillea spectabilis), a vigorous, sprawling vine, can quickly reach 30 feet. Because it has no means of attachment -- except its thorns -- you must tie it to the trellis, fence or arbor. Recommended for U.S. Department of Agriculture plant hardiness zones 9 through 11, bougainvilleas can perform in colder zones if grown in containers and brought inside for the winter. Paper flower bougainvillea (Bougainvillea glabra) grows to no more than 20 feet, and if planted in a container, can be kept to considerably smaller. The tallest hybrids sometimes climb to 40 feet. If you prefer dwarf, shrubby varieties, the unusual "Torch Glow" cultivar features pinkish-red blooms and an erect form that reaches only 6 feet and needs no support. The bronze-red "Temple Fire" offers shrubby growth that stops at 4 feet tall.
Keeping in mind that bougainvilleas bloom on new growth, prune freely to maintain control whenever the plant starts to become too large or sends out a wild shoot. In this way, you can encourage branching without curbing blooming. The best time to trim a bougainvillea back is immediately after a bloom cycle or, in the case of potted specimens, just before moving to a protected area for the winter. Be careful about repotting a plant that appears to have outgrown its container. Restricting the root system has the advantages of deterring rampant growth and encouraging flowering. When you do transplant your bougainvillea, place it in a new container only slightly larger than the old one.
The colorful flowers for which bougainvillea gained its fame are actually modified leaves, called bracts. Within the bracts, the true flowers, small and white, remain inconspicuous. Bougainvilleas bloom most heavily from spring to early summer, with a second flowering in late summer to fall. To ensure that your bougainvilleas bloom reliably, plant them where they will receive six or more hours of direct sun daily. Brighter varieties -- the purples, reds and salmons -- require the most light. White- and yellow-flowered bougainvilleas need some shade in the hottest climates. Normally, keep your plants evenly moist. If they lack flowers, allow the leaves to wilt slightly before your next watering to stimulate blooming.
Growth patterns of different varieties determine where they fit in the landscape. Fast-growing great bougainvillea lends color to fences, arbors and walls. A natural decoration for any Mediterranean-style structure, it works particularly well framing an entrance or a window. The tiny, thornless hybrid, "Vera Deep Purple," makes a lovely flowering bonsai specimen. Bougainvilleas can also serve as ground or bank covers, like the 1 1/2-foot-tall "Oo-La-La." "Raspberry Ice" has a mounding growth habit that works well in a hanging basket.