Tibouchina ‘Purple Star’

Tibouchina 'Purple Star' (Tibouchina 'Purple Star') gives you the deep purple autumn display of the big tibouchinas on a shrub that stops at about 2m tall and 1.5m wide. That size is the point of it. The tree forms need a large garden and an annual reduction, while this one holds its own at the back of a border, in a courtyard or in a large pot.

Why you'll love it

• Colour when the garden goes quiet. The purple flush arrives from late summer into autumn, filling the stretch between summer flowering and winter.
• A garden sized tibouchina. At roughly 2m by 1.5m it fits a suburban block without the yearly hard prune the tree forms demand.
• Fast to establish. Growth is quick in warm weather, so a young plant reads as a real shrub by its second season.
• Built for heat and humidity. It performs through a tropical or subtropical wet season when other flowering shrubs sulk, and bees work the open flowers.

Where it works best

Feature planting. One plant against a green background or a pale wall is enough, since the colour is strong and a single specimen does more than a scattered group.

Small gardens and borders. At the back of a border it gives height without bulk. For a run along a fence, plant 1.2m apart so the canopies touch and the colour reads as a band.

Pots and courtyards. A 400mm or larger pot holds it for years. Potted plants settle at around 1.2m to 1.5m rather than the full 2m.

Growing Tibouchina 'Purple Star' in Australia

Position and climate. Full sun gives the heaviest flowering, with a little afternoon shade helping in hot inland gardens. This is a plant for tropical, subtropical and warm temperate zones. It is frost tender, so in cool southern and tableland gardens grow it in a pot you can move under cover.

Soil. Slightly acidic and free draining. Work compost through the bed and, on clay, plant high on a mound. Keep 75mm of mulch over the roots and clear of the stem. It dislikes lime, so avoid planting hard against fresh concrete.

Water and feed. Water twice a week through the first summer, then deep soak whenever the top of the soil dries. It is not drought tolerant and drops buds if it dries out in autumn. Feed a controlled release fertiliser for acid loving plants in early spring.

Pruning. Trim lightly as soon as the autumn flowers finish. Buds form on growth made during the warm months, so an early trim sets up the next display. Avoid cutting deep into bare old wood.

What to expect when it arrives

This variety is supplied as tube stock: a young single plant, usually ankle height with a few branches. It catches up quickly, reaching around 1m by the end of the second growing season, with a first reliable flowering in the second autumn.

A single tube will not reach the minimum order of $300 before delivery, so most customers order several. Stock is packed upright and delivered Australia wide, delivery from $29.95. Expect a quiet few weeks after planting, then new growth within four to six weeks in warm weather, and our 30 day healthy plant guarantee covers you throughout.

Plant care guides and related reading

• Growing tibouchinas in Australian gardens
• More shrubs sized for small gardens
• Browse the flowering plant range
• Alstonville Tibouchina if you have room for the tree

Common questions

How big does it get, and will it need cutting back every year?

About 2m tall and 1.5m wide. A light trim after flowering keeps it dense, but it does not need the hard annual reduction a 4m tree tibouchina demands.

Will it survive frost?

It is frost tender. Light frost burns the soft growth and a hard frost can kill a young plant. In cold gardens keep it potted and shift it to a sheltered spot for winter.

When does it flower?

From late summer into autumn, which is exactly when most gardens have run out of colour. Feeding in early spring and trimming after flowering both improve the show.