Pruning and Training: Shape a Bougainvillea Showpiece

One principle explains everything about bougainvillea pruning: flowers form on the tips of new shoots. Every correct cut multiplies shoot tips, and every extra tip is a future cluster of colour. A never-pruned plant becomes a sparse, leggy tangle; a regularly pruned one becomes a solid ball of bloom.

The two cuts that matter

• Tip pruning, after every flush: once a branch finishes flowering, cut it back by about a third. It will fork into two or three new shoots, doubling your next display.
• Hard pruning, late February: before the spring flush, cut back long unruly branches, remove dead or crossing wood, and set the plant's overall shape for the year.

Kill the water shoots

Long, green, thorny stems that shoot straight up are water shoots. They rarely flower. Cut them off at the base whenever they appear, in any season.

Training: arches, standards and bonsai

• Arches and trellises: bougainvillea is a scrambler, not a true vine, so it cannot grip by itself. Let a few strong shoots run long and tie them to the structure with jute. Prune the side shoots after each flush to build a dense canopy of colour.
• Standards: train a single strong stem up an iron stake and keep pinching the top into a ball for a striking lollipop tree.
• Bonsai: bougainvillea is one of the world's best tropical bonsai subjects. The trunk ages beautifully, and root restriction produces miniature floral explosions. Any root work should be done in February, removing no more than 15 percent of the root mat.

A word on safety

Wear thick gloves and long sleeves. Bougainvillea thorns are sharp and brittle, and their sap makes a scratch sting far longer than it should. Sharp, clean secateurs make cleaner cuts and fewer regrets.