A tropical plant native to the Amazon rain forest, bougainvillea (Bougainvillea spectabilis) makes a show-stopping attraction in gardens where hot, dry climates prevail. The bright, vibrant flowers in shades of red, pink and orange actually consist of modified leaves called bracts. Bougainvillea thrives in hardiness zone 9 to 11, but the plant also grows well in containers as long as they get moved indoors during the winter.
Bougainvillea needs well-drained, loamy soil made of equal parts sand, silt and clay mixed with organic compost. This soil combination allows nutrients to easily feed the roots of the plant. Avoid water-retaining soil since this causes root rot and leaf spots. Plant bougainvillea in full sun, and make sure night temperatures rarely drop below 60 degrees Fahrenheit.
Bougainvilleas require far less water than many other plants. Over-watering the plants often means the flowers may not bloom. While bougainvillea may take a few years to bloom, cut back the water if no blooms appear when expected. Allow the plant to dry out a bit until flower buds appear, then resume regular watering.
The delicate root system of the bougainvillea requires a fertilizer high in micro-nutrients, such as iron, to help the roots grow properly while also encouraging lots of blooms. During the blooming period, bougainvillea needs to be fertilized regularly. Apply just half of the fertilizer during the rest of the year.
Pruning and Pinching
Since bougainvilleas only bloom on new growth, the plants require regular pinching and pruning. Prune the plant so it grows more branches; these new branches then bear flowers. After the flowers bloom and fade, pinch off the soft tips of young plant stems with your fingers to encourage new, fuller growth. Once the end gets pinched off, the plant starts growing several new stems below each pinched area. Since bougainvilleas bloom several times in one season, new flowers should appear on the new growth within one or two months.
Bougainvillea love to climb, but require help to do so. Provide a trellis, fence or arbor for their long stems to hang onto, then encourage them to climb by tying the stems into place with string. The plants provide even more gorgeous visual interest once their blooms cover these supports.
For most gardeners, the only way to grow bougainvillea requires a container. Plant bougainvillea in a container with regular potting soil that drains well. Once planted, keep the soil most but allow it to slightly dry out between waterings. During the summer, feed bougainvillea with a soluble fertilizer. The plant also grows well when slow release fertilizer gets added to the soil surface in March and August. Pinch and prune the plant as if it grew in the ground to encourage new growth on which flowers will appear.