Sometimes known as glory bushes, Tibouchina (previously called Lasiandra) have begun to show their big sumptuous purple flowers, which will continue all through autumn and sometimes into early winter in Sydney. The most commonly seen one is Tibouchina lepidota 'Alstonville', which throbs with opulent colour when back-lit by the autumnal sun. They open from attractive reddish buds and have curled stamens like claws. These plants became popular about fifteen or twenty years ago and so there are many mature specimens to be seen around nowadays, decorating streetscapes and gardens: Sydney seems to have the perfect climate for them, as it does for many South American plants.
They can be shaped as small trees by training to a single trunk, which is what I have done with mine, due to pure laziness, after years of cutting it back very heavily in late winter so that it would stay around 3 m in height. As a tree it gets to about 5 m; I do still prune it lightly to remove the spent flowers each year. It fits in well with my semitropical-style garden, and its large veined leaves provide welcome background greenery in every season. Tibouchina can be grown in many tasteful planting schemes of pinks, white, blues and other purples, such as with Camellia sasanqua, crepe myrtles, Salvia (especially some of the tall-growing autumn-flowering ones), and Brugmansia. True drama can be achieved by pairing the purple flowers with some of the brilliant orange or red blooms of autumn, such as Canna and Dahlia, the bird-like blooms of Strelitzia or red Pentas. They also look stunning grown against a background of autumn-colouring trees or near autumn-berrying trees or shrubs. Tibouchina flowers are also striking when paired with the foliage of red Iresine herbstii 'Brilliantissima', which glows like exotic cellophane, or the burgundy chenille tassels of annual Amaranthus caudatus, which achieves shrub-like stature by autumn.
There are other species of Tibouchina which grow well in Sydney, including Tibouchina urvilleana which usually has begins its long blooming period in summer and continues into autumn. Its leaves and flowers have a very velvety quality, but it is a more sparse and brittle plant, growing to 3 or 4m. There are also a low-growing forms such as 'Jules' (ht 1 m) and 'Sweet Petite' (ht 1.5 m) both with purple flowers, useful mixers with shrubby perennials, bringing rich autumn colour to smaller gardens.
A different species is Tibouchina multiflora grows to about 2 m tall and has sprays of small blue flowers, set amidst large silky leaves, which have a silvery sheen. It is a fabulous plant and blooms for a long period, from January to April. A taller shrub (ht 2.5 m) with similar panicles of white flowers later in autumn has been called Tibouchina clavata, though that name is not always agreed upon amongst my gardening friends, some of whom call it Miconia. Whatever its name, it is also a welcome addition to the autumn garden!
One of the best Tibouchina I have added to my garden in recent times is Tibouchina 'Jazzie'. I am not sure of its parentage but I first saw it in the garden of Pamela Wallace, where it was flowering magnificently. It grows to about 1.5 to 2 m tall, with stunning deep purple flowers, a white centre 'eye' and white stamens. It can be in bloom almost all year round, but it has its heaviest flush now. It can be trimmed back between flower flushes and pruned more heavily in late winter. It is a good size to form a good background shrub to lower plantings. I like to grow it with Salvia and Dahlia.
This blog was first posted on 9 April 2009; updated 26 April 2020.
18 Oct 20
Although my garden is semi-tropical in nature now, I still have some vestiges from my cottage garden days!
11 Oct 20
Consider training a shrub into a small tree.
04 Oct 20
October is iris time in Sydney gardens: the best are the tall bearded irises and Louisiana irises.
One crowded hour
27 Sep 20
Much can be achieved in regular short stints in the garden.
20 Sep 20
We may not be able to grow massed displays of tulips in our climate, but try some of these South African corms instead.