Although they originated in South America, Tibouchinas have become very much part of the Australian garden.
Because of their tropical origins, Tibouchinas really appreciate warm conditions and don’t usually succeed where there are very hard frosts. These days, though, there are plenty of smaller Tibouchinas that can be grown in pots. This means that, in cold areas, a potted Tibouchina can be moved into a protected spot (even a glasshouse) for the winter, thus enabling it to survive through the cold part of the year.
Ever since Tibouchinas first arrived in Australia, plant breeders have been busy developing new varieties to suit our conditions. Tibouchina ‘Alstonville’, one of the most popular, even carries the name of the north coast NSW town where it was developed. ‘Alstonville’ was bred by Tibouchina enthusiast Ken Dunstan, who was one of the first Australians to appreciate the potential of these plants. It grows to small tree size and smothers itself in rich purple flowers through much of late summer and autumn.
Another Dunstan cultivar, ‘Kathleen’, also reaches small tree size. Its lolly-pink flower sprays provide a refreshing change from the widely grown purple.
‘Noeline’ offers gardeners something quite unusual: a Tibouchina with flowers that change colour as they age. The flowers start off white and gradually mutate to a deep, mauve-pink. The various shades seen on the plant at the one time create an attractive, multi-coloured effect. To add to its interest, ‘Noeline’ tends to flower in early summer, well before most of its relatives.
‘Jules’ is a small Tibouchina that reaches about 1 metre and does well in a pot or a mixed border. Its flowers are similar to the deep purple blooms of ‘Alstonville’, but the plant’s compact size makes it easy to place in the landscape.
Queenslander Terry Keogh has now followed in Ken Dustan’s footsteps and is developing new Tibouchinas that are ideal for today’s smaller gardens. The first to be released in his Fantasy Flower collection was ‘Groovy Baby’, an ideal pot specimen that grows 60cm tall and 80cm wide. This purple-flowered beauty was followed by similarly-sized ‘Peace Baby’, with crisp white flowers that are decorated with eyelash-like, pink and purple stamens. Both ‘babies’ are said to have enhanced cold tolerance. Watch this range, as there are many more to come.
As mentioned, these warmth lovers will need some protection to get them through winter in cold climates. Move to a covered porch or glasshouse. A spray with Yates DroughtShield when cold temperatures are predicted can help.
Feed Tibouchinas in spring, summer and after flowering with a long lasting, bloom-boosting fertiliser such as Yates Dynamic Lifter Soil Improver & Plant Fertiliser. Keep well-watered when it’s hot and dry (like most tropical plants, they need plenty of water, but good drainage). Prune after flowering or, if winters are cold, in early spring.