Australian native trees for shade: what to plant near a house

Shade is the one thing a garden cannot fake. A pergola helps, but it does not cool the air, drop the surface temperature of a driveway or make a west-facing wall bearable in February. A tree does. The question is not which native tree looks best in a nursery photo, it is which one you can still live under in twenty years.

The gum tree problem, stated plainly

Eucalypts shed limbs. So does every large tree, but eucalypts have a reputation for doing it in still, hot weather with no wind to blame. The phenomenon is real, and it is not evenly distributed: it is overwhelmingly a problem of large, old, forest-sized trees carrying long horizontal limbs under heat and moisture stress.

Almost every failure we hear about traces back to one decision made fifteen years earlier, putting a tree with a mature height of 25m or more within a tree length of a house. Nothing you do afterwards fixes that, and pruning a large gum to keep it off a roof produces regrowth more poorly attached than what you removed.

So the rule for gum trees is not "avoid them", it is:

• Match mature height to the site. If the distance from trunk to house is less than the mature height of the species, choose a different species. Mature height varies enormously across the genus, so read it on the product page rather than assuming.
• Get formative pruning done in the first five years. Removing a competing leader or a steeply angled fork at 40mm is a five minute job. At 400mm it is a crane.
• On acreage, with room to let a big gum be a big gum well clear of buildings and parking, they are excellent and there is no reason to avoid them.

Angophora or eucalypt? How to tell

Three genera share the "gum" label: Eucalyptus, Corymbia (the bloodwoods and spotted gums, split out of Eucalyptus in the 1990s) and Angophora (the apples). If you have an existing tree on site, the reliable tells are:

• Leaf arrangement. Angophora holds its adult leaves in opposite pairs. Eucalyptus and Corymbia hold adult leaves alternately along the stem. It is the quickest check.
• Flower buds. Eucalyptus and Corymbia buds have an operculum, the little cap that pops off as the flower opens. Angophora has no cap. Its buds show separate small sepals and petals.
• Fruit. Angophora gumnuts are strongly ribbed. Corymbia fruit is typically urn shaped. Eucalyptus fruit varies but is rarely as deeply ribbed as an angophora.
• Bark and habit. Sydney red gum, Angophora costata, is the one most people recognise: smooth salmon to orange bark, and heavy, sinuous, near horizontal limbs.

Identification is not selection, though. Angophora is not a safer choice than eucalypt: Angophora costata has the heaviest horizontal limb architecture of the three. Knowing the genus tells you what to expect from the tree you have. It does not change the siting maths for the tree you are about to plant.

Four better choices for a suburban shade tree

These are the genera we point landscapers at when the brief is shade over a courtyard, a deck or a north-west wall on a normal block. All are in the native trees range, and none of them is trying to become a forest tree.

Brachychiton

The kurrajong, Brachychiton populneus, is the drought tree of this list. It puts down a deep taproot rather than a mat of surface roots, which is what you want near paving, and holds a dense evergreen crown through the worst of summer. Slow to moderate, long lived, tough once established. Brachychiton acerifolius, the Illawarra flame tree, is the deciduous relative grown for its flowering, so it is a feature tree first and a shade tree second.

Lophostemon confertus

Brush box is the workhorse. In rainforest it is a big tree, but in open suburban planting it typically settles around 10m to 15m with a dense, rounded, evergreen canopy that casts real shade rather than dappled light. It tolerates heat and reflected glare, which is why councils across Brisbane and Sydney have used it as a street tree for decades. If you want one tree to shade a driveway and not cause trouble, this is it.

Tristaniopsis laurina

Water gum or kanooka. Smaller again, usually under about 10m, smooth barked and neatly upright. It tolerates periodic wet feet, so it suits a low corner, a swale or the bottom of a slope where other trees sulk. It is also the standard choice for a tree pit in paving.

Elaeocarpus

Blueberry ash, Elaeocarpus reticulatus, is the courtyard option: narrow, dense, generally 5m to 8m, with fringed bell flowers and blue fruit. It lacks the spread to shade a lawn, but it will shade a small paved area or a window without threatening the slab, and it doubles as a privacy screen planted in a row.

Three to think twice about. Figs and ficus make generous shade on acreage and are a bad idea within reach of a house, a pool or a sewer line. Wattles establish faster than anything else here, but many species are short lived, so treat a wattle as a nurse tree that buys shade for ten or fifteen years while the real tree grows. Paperbarks are tough and tolerant of wet ground, but check mature height species by species.

Root zones, paving and setbacks

Roots do not hunt for pipes. They grow where there is moisture and oxygen, which in a suburban yard means the top 300mm to 600mm of soil, spreading well past the dripline. Paving lifts because lateral roots thicken under a slab poured onto compacted subgrade with no root barrier and no moisture anywhere else nearby.

Tree	Typical height in a garden	Setback from slab or services	Notes
Elaeocarpus (blueberry ash)	5m to 8m	3m to 4m	Narrow crown, suits courtyards
Tristaniopsis (water gum)	Usually under 10m	4m to 5m	Handles paving and periodic wet ground
Brachychiton (kurrajong)	10m to 15m	6m to 8m	Deep taproot, little surface rooting
Lophostemon (brush box)	10m to 15m	6m to 8m	Dense shade, well behaved roots for its size
Large gums and angophoras	20m and up	Acreage only, clear of the fall zone	Judge by mature height, not by nursery size

Treat those setbacks as a rule of thumb, not a code. On reactive clay they should go up, sometimes a long way up, because the issue is no longer root pressure but soil shrinking as the tree draws moisture from under a footing. If your block is clay and the tree is going near the house, that is a question for the engineer who did your slab.

Three things that protect paving:

• Leave a generous unpaved area around the trunk. A 1m square cutout in a driveway is not a root zone, it is a plant pot with no bottom.
• Install a linear root barrier along the slab edge at planting time, not after the paving starts moving.
• Water deeply and infrequently from the start. Light daily watering trains roots into the top 100mm, which is exactly where they cause damage.

What size to buy

Shade is the outcome where buying advanced stock genuinely changes the timeline. A semi advanced tree gives you several years of head start over a small pot, and advanced trees and 100L stock arrive already reading as trees rather than sticks.

It does not scale forever, though. Very large stock carries proportionally less of its root system into the ground and spends longer recovering, so a well grown 45L or 100L tree will often catch a 400L tree of the same species within a few years, especially if the big one is not watered properly through its first two summers. Buy the largest size you can water reliably, not the largest available. Stake low and loose if at all, keep mulch off the trunk, and water by volume rather than by minutes on the tap.

To shortlist, start with the native range for the four genera above, browse feature trees if it will be looked at as well as sat under, and check gum trees if you have the acreage to do a big eucalypt properly. Delivery is a flat $99 to QLD, NSW, VIC, SA, ACT and WA, so trees, screening and underplanting cost no more to freight together than the trees alone.

Plants featured in this guide

Everything below is currently available farm-direct, with flat $99 delivery in QLD, NSW, VIC, SA, ACT and WA and a $399 minimum order.

• Lemon Scented Gum - Corymbia citriodora Dwarf (Eucalyptus citriodora) from $48.95
• Red Flowering Gum - Corymbia ficifolia Rivetts Pink (Eucalyptus ficifolia) from $48.95
• Red Flowering Gum - Corymbia ficifolia Rivetts Orange (Eucalyptus ficifolia) from $48.95
• Lemon Scented Gum - Corymbia citriodora Herberton (Eucalyptus citriodora) from $39.95
• Gum Tree - Eucalyptus platypus subsp. platypus from $48.95
• Snow Gum - Eucalyptus pauciflora debeuzevillei from $48.95
• Blue Box - Eucalyptus baueriana ssp. Thalassina from $39.95
• Sydney Red Gum - Angophora costata from $29.95
• Lemon Scented Gum - Corymbia citriodora Sinuous (Eucalyptus citriodora) from $40.95
• Narrow-Leaved Apple - Angophora bakerii from $39.95
• Gum Tree - Eucalyptus saligna from $29.95
• Yellow Gum - Eucalyptus leucoxylon subsp. leucoxylon from $149

Browse the full range: Gum Trees · Australian Native Plants · Kurrajong

Related ranges: Banksias, Tea tree and leptospermum.