Blue Tongue

Blue Tongue (Melastoma affine) is an Australian native shrub of about 2m tall and 1.5m wide that carries purple and pink flowers over a long season in a warm garden. The berries that follow are edible and stain your tongue blue, which is exactly how the plant got its name. It grows quickly and thrives in damp ground that would kill most flowering shrubs.

Why you'll love it

• Flowers over a long season. Purple and pink blooms open in flushes rather than one short burst, so a mature shrub is rarely without them in a warm climate.
• Edible berries. The fruit that follows the flowers is edible and sweet, and it stains the mouth a striking blue.
• A wildlife plant that earns its keep. Birds take the fruit and native bees and butterflies work the flowers.
• It wants the wet corner. Wet feet tolerant, so the damp low spot or rain garden that defeats other shrubs suits it perfectly.

Where it works best

Mass planting and informal screening. Plant 1m apart for a massed informal screen. It will not clip into a formal hedge, but at that spacing it makes a soft flowering barrier around 2m high.

Damp and low lying ground. Creek banks, drainage swales, rain gardens and the corner of the block that stays soggy after rain are all genuinely good positions for it.

Feature planting. A single well grown shrub carries enough flower and fruit to hold a bed on its own, particularly in a native or bush garden.

Growing Blue Tongue in Australia

Position and climate. Full sun gives the most flower, though it accepts part shade. This is a plant for tropical, subtropical and warm temperate gardens, and it is frost tender, so cold inland districts and frosty southern gardens are unsuitable.

Soil. Adaptable, and unusually tolerant of soils that stay wet. It prefers a moisture retentive, slightly acidic bed with compost worked through, and it will not thrive in dry alkaline ground.

Water and feed. Keep the water up through the first two summers, and afterwards in dry spells, because dry soil checks both growth and flowering. A native fertiliser in early spring is enough for the year.

Pruning. Tip prune after each flowering flush to keep it bushy rather than open and twiggy. It reshoots readily, so an older plant that has thinned out can be cut back hard in spring.

What to expect when it arrives

It is grown as tubestock, in 140mm pots sold in packs of ten, and in 200mm pots sold in packs of six. Tubes are the economical choice for a mass planting, and they catch up quickly. The 140mm and 200mm plants are already branching and reach screening height a season sooner.

Some leaf drop in transit is normal for a soft leaved native. Plant it out while the weather is warm, keep the water up, and expect flowering from the second season. Delivered Australia wide, with delivery from $29.95, and every plant carries our 30 day healthy plant guarantee.

Plant care guides and related reading

• Browse the full range of Australian native shrubs
• Native plants that attract birds
• What to plant in a waterlogged garden
• Compare other edible plants

Common questions

Is the fruit actually edible?

Yes. The berries are a traditional bush food, sweet and soft when fully ripe, and they turn the tongue and lips blue for an hour or so. Pick them when they split open naturally.

How wet can the soil be?

Wetter than most shrubs will accept. It handles ground that stays damp and periods of waterlogging after rain, though it still prefers soil that drains eventually rather than a permanent pond.

Will it survive frost?

No. It is frost tender, so it suits tropical, subtropical and warm temperate gardens only. In marginal areas a warm sheltered wall may carry it through, but a hard frost will cut it back.