Gum Tree Eucalyptus rudis

Along the Swan Coastal Plain and the damp flats of the south west, Flooded Gum is the tree that holds the low ground. Also known as moitch, it tolerates heavy clay and seasonal waterlogging that would drown most trees, so it lines creeks and fills paddock corners that go under every winter. It builds a broad, spreading crown over a short, rough barked trunk with smooth pale limbs above, and white blossom in the cooler months. Shade on wet ground is its job.

Wet clay flats, and the lerp that follows stress

Perth, the south west and similar mediterranean climates suit it, and it transfers to damp sites in South Australia and inland Victoria and New South Wales where winters are wet and summers are dry. Full sun. Heavy clay is not a problem and neither is a flat that sits under water for weeks, so it earns its place where drainage work would otherwise be needed. Growth is fast in open ground, and once the roots reach the water table it asks for very little from you. Keep it well clear of drains, footings and septic lines, because the roots are vigorous and they follow moisture.

In urban gardens the predictable trouble is insect damage. This species is a favourite of psyllids and lerp, and a stressed tree gets hammered, defoliating and looking wretched by late summer before it slowly recovers and does it again the next year. Stress is what invites the attack: compacted soil, grass to the trunk, root damage from trenching, and long dry spells without relief. Mulch it, keep traffic off the root zone, and water in extended dry weather even though the species is drought tolerant.

Flooded Gum against the yate and the tuart

Set against flat topped yate, the other Western Australian wet ground specialist, this one gives a better shaped shade tree but does not match it for salt tolerance, so on scalded saline ground the yate wins. Tuart is the opposite site altogether, a limestone sand tree that will not accept the wet clay Flooded Gum lives on. Pick Flooded Gum for damp, heavy, non saline ground where you want a broad crown and a fast result. Bark is the quick way to separate it from the tuart in the field, since this species carries only a short rough stocking at the base under smooth pale limbs, where the tuart is rough grey fibre from the ground to the branch tips. On a mixed property there is room for both. See more in natives.

Shape it early, then manage stress rather than pests

Do the formative pruning in the first three or four years, in late winter. Select a leader, shorten the competing stems rather than cutting them off flush, and lift the canopy gradually if you need clearance for stock or mowing. Avoid large cuts on established trees. Feeding is not the main lever here. A low phosphorus native fertiliser in spring for the first two seasons is enough, and after that the useful work is mulch, grass control and keeping the tree unstressed, which is also the practical defence against lerp. Do not spray a large tree for psyllids. Feeding the soil and leaving the predatory insects alone works better over a season.

Choosing a size

This plant is available in 3 sizes, from 5L up to 90L, priced from $29.95 to $479.00 per plant. The size shown is the pot the plant arrives in, which is the rootball, not the height of the plant. Every size here is established stock rather than a starter plant, so this line is intended for immediate effect rather than for growing on. Not sure which to choose? Read our guide to Australian native trees for shade.