Bougainvillea (Bougainvillea spp.) grow quickly and need pruning in order to keep them from taking over your yard. In fact, in U.S. Department of Agriculture plant hardiness zones 9 through 11, they grow all year long and bloom multiple times per year. If you don't keep them under control, you'll quickly find that bougainvillea has infiltrated your entire garden. Established plants may need pruning several times per year. Because the plants are thorny, take care to protect your hands and skin while pruning.
Best Time to Prune
It's best to prune bougainvillea in late spring, after it's already flowered, or in late winter after it flowers again.
Bougainvillea grow rapidly, making it difficult to keep them in the shape you prefer. That, and the fact that they have thorns, means may need to prune them more often than early winter or late spring. Their hardy nature means they can tolerate
Just be careful not to prune too aggressively in the summer or fall, warns the University of Florida, or your bougainvillea might not produce as many blossoms in the following seasons. One strategy is to ease overcrowding by trimming back lateral stems so they only contain about three buds.
The best tool for pruning your bougainvillea is a sharp pair of pruning shears designed to cut through woody stems and vines. In established plants, the thick, woody vines will be too tough for garden scissors. Make sure you disinfect your gardening tools to prevent the spread of disease and pests among your plants.
One of the easiest ways to clean your pruning shears is to soak them in a simple mixture of 1 part bleach to 9 parts water for 30 minutes. You can also wipe your shears liberally with a 70 percent or higher solution of ethanol or isopropyl alcohol.
Bougainvillea have an abundance of sharp thorns. The vines also contain sap that can cause a painful and itchy rash. Whenever you work with bougainvillea, it's important to wear thick gloves and long sleeves to avoid the thorns.
If you do come in contact with the thorns or sap and experience a reaction, clean you skin with warm, soapy water and apply a cool compress. You can also use over-the-counter antihistamines or anti-itch creams. If you don't get better in a few days, contact your doctor.
Getting Down to Business
There are no hard-and-fast rules for maintaining the shape you want to achieve with your bougainvillea. Simply use your pruning shears to cut away any vines that appear out of place or that have grown too long. Use sharp shears and make clean, fast cuts to minimize damage to the plant. According to the Royal Horticultural Society, bougainvillea can withstand vigorous pruning, so don't worry about cutting away too much.