Autumn glory

Thursday, 09 April 2009

Tibouchina Alstonville

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.

Tibouchina Alstonville with Salvia elegans Golden Delicious

They can be shaped as small trees by training to a single trunk, which is what I have now done with my new one, due to pure laziness, after years of cutting it back very heavily in late winter so that it would stay around 3m in height. I am not sure how tall it is going to get as a tree, but at the moment 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 1m) and 'Sweet Petite' (ht 1.5m) both with purple flowers, useful mixers with shrubby perennials, bringing rich autumn colour to smaller gardens.

Tibouchina Elsa

In late summer, I had a couple of other smaller-growing species in bloom: Tibouchina multiflora grows to about 1.5-2m tall and has sprays of small blue flowers, set amidst large silky leaves. 'Elsa' (ht 1m) has similar flowers, but they are white with purple stamens, which makes for a very striking combination. A taller shrub (ht 2.5m) 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!