The bougainvillea is a tropical vine whose bright, vibrant flowers positively glow in the landscape. Bougainvilleas can produce up to two or three beautiful displays of flowers in spring, summer and fall. The colorful parts are actually modified leaves called bracts. The true flowers are small and white.
Taking care of bougainvilleas is not difficult. The most common problem people seem to have is getting them to bloom. The following advice is designed to produce a healthy plant with the best chance to bloom.
The first step is to provide your plant with as much light as possible. Bougainvilleas bloom best when they receive direct sun most of the day. In New Orleans and other parts of costal Louisiana, bougainvilleas are sometimes planted in the ground in a protected location. Sooner or later, however, a winter severe enough to kill them will come along. Also, bougainvilleas in the ground grow rampantly and are reluctant to bloom for one to two years after being planted; however, if winters are mild and there is enough room for its large size, a bougainvillea growing in the ground can put on an amazing floral display.
For most of us, container culture generally gives best results. You don’t need to use any special type of soil mix. Any good potting soil is fine as long as it drains well. Fertilize bougainvilleas regularly during the summer with a soluble fertilizer. Slow-release fertilizer may be applied to the soil surface in March and August. If your container-grown bougainvillea begins to grow rampantly, producing large, dark-green leaves, you have probably overfertilized your plant.
You should grow bougainvilleas in relatively small containers. Don’t be in a hurry to repot them when they look like they have outgrown the pot they are in. Restricting the root system to some extent will not hurt as long as they are well watered and fertilized, and it encourages flowering. Eventually, you will have to move the plant to a larger container. When you do so, the new container should be no more than 2 inches larger than the original one.
Like all plants, bougainvilleas need adequate moisture for proper growth. Keeping the plants evenly moist, but allowing them to dry slightly between waterings, is generally recommended. If your plants seem reluctant to bloom, growing them a little more on the dry side will help encourage flowers. This is a little tricky, but the technique involves letting the plant wilt slightly between waterings. If you let the plant dry out too long though, you will damage it. As soon as flower buds appear, generally in about three or four weeks, resume normal watering. If you let a blooming bougainvillea wilt severely, it will drop its flowers.
Since bougainvilleas bloom on new growth, feel free to cut them back to keep them under control and encourage branching. An ideal time to cut back bougainvillea is right after they finish a bloom period. Don't prune too often, however. Constant pruning to keep a plant from getting too large can inhibit blooming. Bougainvilleas may be kept bushy, allowed to sprawl and trail or trained on a trellis, whatever your taste or situation dictates.
With careful attention to these cultural guidelines and patience, you should be rewarded with the brilliant flowers for which these vines are so well known.