Macadamia Nut Macadamia integrifolia

Macadamia integrifolia is a dense, dark evergreen rainforest tree from the coastal ranges of south-east Queensland and northern New South Wales. It holds its leaves in whorls of three with smooth, untoothed margins and green new growth, which is the quickest way to separate it from Macadamia tetraphylla and its four-leaved, prickly, pink-flushed whorls. Long hanging racemes of cream flowers follow, then nuts in green husks. In a garden it works as a shade and shelter tree that happens to feed the household.

Soil, shelter and the rot that ends most home macadamias

The warm coastal strip suits it, and anywhere frost settles a young tree needs a protected spot until the trunk hardens. Full sun to part shade both work, though a tree in shade flowers on fewer branches and carries a lighter crop. Give it deep, free-draining soil with some organic matter worked through, keep it out of the wind funnel between buildings because the limbs are brittle and the roots sit shallow, and mulch widely instead of digging around the base. The failure mode is root rot. On heavy clay, or in a low spot that stays wet after summer storms, Phytophthora will take a healthy tree out over a couple of soggy seasons, and by the time the canopy thins the roots are already gone. Plant on a raised mound if your soil holds water, keep the root collar clear of mulch, never build soil up against the trunk, and water steadily through establishment and again while the nuts are filling rather than keeping the ground permanently damp all season.

Macadamia against the other evergreen natives here

Set beside Tuckeroo, the macadamia is fussier about drainage, slower to build a canopy, and far messier underfoot once it bears. Tuckeroo takes salt wind and sand and its litter is small. Tulipwood gives a similar dense rounded crown with better street manners and no crop to sweep up. Choose macadamia if you want the nuts and have open ground clear of paving, mowers and the barbecue, because husks underfoot are genuinely slippery and the fallen nuts draw rats. One caveat before it goes into a family garden: macadamia nuts are toxic to dogs, and a dog that scavenges the drop can end up weak, wobbly on its back legs and vomiting within hours, so plant it where the fallen crop can actually be picked up rather than over open lawn a dog runs on. Choose tuckeroo or tulipwood if the job is shade or screening on a suburban block, or if the tree has to stand near a driveway, a pool or a path that children use. Plan this one with the fruit trees, not with the ornamentals.

Pruning, harvest and why phosphorus matters

Shape the young tree to a single leader with well spaced side branches, and lift the lower limbs if you want to mow underneath. Do the structural work after harvest, once the last nuts are off, so you are not cutting away the older wood that carries next season's flower racemes. Mature trees need little beyond removing crossing, rubbing and dead branches, and thinning to let light into the centre. Feeding is where people come unstuck. Macadamias are Proteaceae and sensitive to phosphorus, so use a low phosphorus native or macadamia specific fertiliser in spring and again after harvest, and keep general purpose lawn feeds and poultry manure well away from the root zone.

Choosing a size

This plant is available in 4 sizes, from 250mm up to 300L, priced from $76.95 to $2269.00 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.