Bougainvillea bloom in cycles, with months of vigorous blooming followed by rest periods. Pruning before the beginning of a new cycle allows the vine to produce vigorous new growth. The exact month of the year during which bougainvillea should be pruned differs by region. The easiest way to tell whether it’s time is to simply check the weather or the Farmer’s Almanac. [2] X Research source When the last chance of frost has passed, but before the vine has begun to bud, it’s time to prune.
Remember to wipe your pruning shears with the disinfectant after pruning diseased branches before pruning healthy branches to prevent disease from spreading. Remove the diseased branches from the area, so they don’t contaminate the plant.
Bear in mind that with each cut you make, new branches will emerge. Pruning helps the plant grow thicker and bushier. If you see an area that looks stringy, make a strategic cut to help it branch out there. Many bougainvillea are trained to grow up a trellis or along a fence. As you prune, you can gently wrap new shoots around the structure to which the plant is being trained, to encourage growth in that direction. Bougainvillea shrubs can be pruned to achieve all sorts of shapes. If you’re growing yours in a pot, you can even prune it to take on the shape of a small tree.
You can remove dead wood from the plant by trimming it at any time of year, but save the bigger pruning cuts for early spring, when the plant won’t get damaged.
Be sure not to wait too late in the season, though, since toward the end of the cycle it will be too late to encourage new blooms. Don’t cut into the old growth until early spring.
