The bougainvillea is a tropical vine whose bright, vibrant flowers positively glow in the landscape. Bougainvilleas can produce 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. There are many, many different types of bougainvillea varieties on the market, and they can vary tremendously in how reliably and how often they bloom. The following advice is designed to produce a healthy pant 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 full sun most of the day.
In New Orleans and milder areas of Louisiana, bougainvilleas are sometimes planted in the ground in a protected location that gets sun all or most of the day. Handled this way, they make huge, spectacular plants that produce amazing displays of flowers. Cold can be an issue, and substantial winter damage will occur when temperatures hit the mid to low twenties. But, as long as winters are mild the plants will thrive and bloom on and off through the summer into the fall. Flowering will be greatly reduced for a year or two if the plants get frozen back.
Bougainvilleas planted in the ground, however, grow rampantly and are reluctant to bloom for a couple of years after being planted. You must be prepared to manage and train the explosive growth they are capable of producing. Few, if any, flowers will be produced until the plant gets settled into its new location and growth slows somewhat, generally a couple of years (sometimes more) after it is planted in the ground. This is not a nutritional problem. Indeed, fertilization and irrigation will likely delay flowers. These plants tend to bloom better when neglected. If you are patient, however, as the years go by you will eventually have a large plant that blooms prolifically as long as winters are mild.
Where hardiness is an issue or when a large plant is not desired, 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. Should your container-grown bougainvillea begin to grow rampantly, producing large, dark-green leaves, you have probably over fertilized your plant. If that happens, stop fertilizing.
You should grow bougainvillea in relatively small containers. Don’t be in a big 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 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 two 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, however, 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 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. 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 the cultural guidelines presented here and patience, your bougainvilleas should reward you with the brilliant flowers for which these vines are so well known.