A spectacular sight in the tropics and hot coastal areas of the Americas is the ever-blooming bougainvillea, a shrubby vine covered with bright and gaudy blossoms.
Named in honor of L.A. de Bougainville, a French navigator who lived from 1729 to 1811, bougainvillea is native to South America. First described and classified in 1789, bougainvillea had been discovered in Brazil twenty years earlier.
Since their petals resemble paper, bougainvillea is popularly known as Paper Flowers.
Botanically, bougainvillea is classified as Bougainvillea glabra, Bougainvillea peruviana, or Bougainvillea x Buttiana (a hybrid of the previous two.)
There are other species, but most commercial varieties are selections and hybrids of these three main species. New hybrids appear regularly.
The flowers we associate with bougainvillea are red, purple, pink, lavender, orange, white, and bi-color bracts. True bougainvillea flowers are small, white, and tubular, appearing inside these colorful papery bracts.
Usually, bougainvillea grows as thorny vines, but recent efforts have produced mostly thornless hybrids. Another trend is toward developing shrubby plants with more compact habits for container growing.
Light & Bougainvillea
Sunlight is probably the most critical factor in bougainvillea cultivation. Bougainvillea needs full to 3/4 sunlight — no less — or it won’t bloom.
A common misconception is that bougainvillea bloom only during the fall, winter, and spring. Bougainvillea can bloom all year if grown correctly in good light.
Growth in the winter can be retarded if plants get too cool. A hot greenhouse will encourage new growth, which leads to repeat flowering.
Watering
NEVER let potted plants wilt during the blooming period or stand in too much water. Bougainvillea needs a “happy medium.”
After planting in the ground, hold back on watering slightly until the bougainvillea begins to expand its roots — then water as necessary.
Fertilizing
A top-dressing with “ColorStar” bougainvillea fertilizer will get the growth off to a good start. Incorporating a well-balanced slow-release coated fertilizer into the soil at planting time will encourage growth and blooming for a long time.
Too much nitrogen in the fertilizer will cause excessive leaf growth, leading to delayed or aborted blooming.
Iron is vital for good green color but tends to be unavailable to bougainvillea plants during cold winter weather. Soluble, granular iron works well and, unlike sprays, won’t stain leaves and blooms.
Pruning Bougainvillea
Bougainvillea bloom on new growth. With proper pruning, sunlight, and water, plants will repeat a blooming cycle in about 4 weeks.
A rule of thumb is to prune, once the blooming is over, one-half of the growth ending in a bloom. For example, if the growth where blooming occurs has grown out 6 inches, prune off the old bloom cluster, plus 3 inches of the stem after blooming.
Also, “pinching” the tips of your bougainvillea encourages new growth and flowers and maintains a compact, manageable plant.
Planting Bougainvillea
For winter protection of in-ground plants, mound or “bank” soil 6 inches over the roots and lower plant stems.
Leave this all winter and allow the outer stems to freeze. Once the chances of freezing have passed in the spring, cut the plants back to this soil mound and wash the mound away, leaving the lower stems exposed.
With steady light, warm temperatures, and watering, bougainvillea should begin budding in about 4 weeks.
Keep potted bougainvillea plants out of 32 degrees and colder weather by moving them inside for the duration of freezing temperatures.
If the leaves burn from wind or frost, give your plant good warmth and light. It should begin growing back within 10 to 20 days and bloom in the expected 4-week time frame.
Controlling Pests
Aphids are the most common bougainvillea pest we encounter. If you have a problem with aphids or other insect pests, bring bug samples or photos of them into Anawalt for identification. We’ll recommend measures for pest control.