Water Gum Tristaniopsis laurina (Tristania laurina)

The bark is the reason councils plant water gum by the thousand: it sheds in plates off a smooth trunk, leaving a mottled surface of cream, tan and grey that changes through the year. The leaves are glossy and dark, new flushes push through coppery before they harden off, and small clusters of yellow flowers sit through the warmer months. The crown stays dense and rounded rather than sprawling, and the roots are restrained enough for verges, car park islands and courtyards close to paving.

A creek line tree in a paved world

It grows wild along creek lines on the east coast, and that origin explains everything about its behaviour in gardens. Full sun to part shade both suit it, water needs are moderate, growth is moderate to fast, and it copes with soil that stays damp longer than most trees will tolerate, which is why it works in a low corner or beside a downpipe outlet. It still wants a deep soak through a dry summer even after several seasons in the ground. Space plants two to three metres apart for a screen. The failure mode is scale. Soft scale builds up along the stems and leaf undersides, the insects drip honeydew, and sooty mould follows as a black film across the foliage that dulls the whole tree and takes months to weather off. Watch for ants running up the trunk, which is the early sign, and treat before the mould sets in. Young trees also scorch at the leaf margins where hot dry wind reaches them without shelter, so give them cover for the first couple of summers. Neither problem is fatal, and both are far easier to stay ahead of than to fix.

Water gum, tuckeroo or tulipwood

The three overlap heavily on paper and separate on site. Water gum is the one to plant where the ground holds moisture and where the trunk will be seen, since neither of the others offers that mottled shedding bark. Tuckeroo is tougher in salt wind and pure sand, and its fruit brings birds that water gum does not. Tulipwood gives the glossiest foliage and the cleanest street manners inland. Choose water gum for damp ground, bark character and a tight crown near paving, tuckeroo for the beachfront, tulipwood for an inland suburban street. Water gum is also the one to pick where the tree has to sit close to a slab, a kerb or a boundary, because its root behaviour is the most predictable of the three. Larger stock sits in the mature trees range.

Timing a trim, and staying ahead of the scale

Prune after the yellow flowers finish, in late summer, which keeps the crown even without cutting off next season's display. It responds well to light annual shaping and can be lifted for clearance over a footpath, but avoid cutting back hard into old wood. Deal with scale in spring: a horticultural oil spray to run-off, repeated a fortnight later, then hose the sooty mould once the insects are gone. Feed in early spring with a controlled release native fertiliser, mulch out to the drip line, and keep the mulch off the trunk so the bark can shed cleanly. Trees under paving stress benefit more from a deep monthly soak in summer than from extra fertiliser.

Choosing a size

This plant is available in 8 sizes, from 140mm up to 100L, priced from $17.95 to $649.00 per plant. The size shown is the pot the plant arrives in, which is the rootball, not the height of the plant. The smaller pots hold younger plants that cost less each and establish quickly, which suits hedges, screens and mass planting where the plant count adds up. The larger sizes carry several more years of growth on the farm and give height and presence straight away, which is what you want for a single feature position or a screen that cannot wait. Not sure which to choose? Read our guide to Australian native trees.