Tibouchina urvilleana is a dramatically flowering subtropical evergreen shrub native to Brazil, and known colloquially as princess flower. Tibouchina can reach 15 feet in height, and can easily be trained into a small standard tree form. The shrub has a long flowering period from May to January each year. The blooms are also unique, with a vibrant and rich violet hue that is somewhat startling in the landscape and reminiscent of orchids. Pruning requirements are few, but the shrub can tolerate and recover from extensive pruning when required.
Prune your tibouchina shrub in the winter or early spring after the blooming period has finished for the year.
Prune away any dead, damaged, crossing or abrading branches, cutting back to healthy wood.
Reduce the height and sprawl of the shrub by shearing back the terminal branch tips to the desired length. Remove up to two-thirds of the branch length, if necessary, but no more. This will spur new, more compact and dense branch and foliage growth. Flowering may be diminished very slightly the following year, or it may not, as the species is known to be fast-growing.
Train young shrubs into standard tree forms by removing the branches, sprouts and limbs from the lower third to half of the main shrub trunk. Consistently remove any new growth along the trunk and at the soil line until no new shoots appear.
Use secateurs on small branches of less than 1/2 inch in diameter, and use a finely toothed pruning saw for larger branches and limbs to ensure clean cuts. Shears are helpful for reducing the overall height and spread of the shrub.