Tibouchina urvilleana is grown as indoor plants but require some special conditions and are unlikely to thrives without them. It has a fairly narrow margin for error: leaf drop and plant decline are unfortunately common, most often because of watering or temperature issues.
It is a fast growing shrub. Shorten main shoots by half their length and cut side-shoots back to two pairs of leaves each spring. In this way the leggy growing habit of Tibouchina urvilleana is kept under control and will enhance the flower display.