Macadamia tree

How to identify a macadamia

An evergreen tree with stiff, glossy leaves set in whorls along the stems. Macadamia integrifolia has leaves 7 to 15 cm long, mostly in threes, with wavy edges that are smooth or carry a few prickly teeth, and pale green new growth. Macadamia tetraphylla has longer leaves, 18 to 25 cm, usually in fours, edged with regular stiff prickles, and reddish new growth. In late winter and spring, sprays 10 to 25 cm long of small cream, pink or mauve flowers appear, followed by round green husks 2 to 3.5 cm across. Inside is the very hard nut: smooth-shelled in integrifolia and rough in tetraphylla.

Growing a macadamia in Brisbane

Macadamias are true locals. Both species grow wild in subtropical rainforest in south-east Queensland and northern New South Wales, and Europeans first came across them just north of Brisbane in the 1830s. Wild trees are now scarce: Gardening Australia reports that more than 80 per cent of bush macadamias have been lost, though some survive in bushland around Brisbane. In gardens they want good drainage, deep topsoil, shelter from strong wind and protection from frost while young, and they die in soil that stays waterlogged. Nuts mature and fall from about March to September.

What to watch out for

Mature nuts fall over many months, roughly March to September, so expect to collect nuts and husks under the tree for much of the year. The leaves of Macadamia tetraphylla in particular are edged with stiff, prickly teeth, so wear gloves when pruning. Standard trees can reach 12 to 15 metres, so choose a compact cultivar for a small yard. Rats are attracted to the nuts. Macadamia isn't on any Brisbane or Queensland weed list.

• Falling fruit. Mature nuts in their husks drop to the ground over several months, from about March to September.
• Spines. The leaf edges can carry stiff, prickly teeth, most regularly on Macadamia tetraphylla, so wear gloves when pruning.

Pruning and care

Plant in late autumn so the roots can settle before summer heat, into well-drained soil with plenty of organic matter. Like grevilleas and banksias, macadamias are sensitive to phosphorus, so feed them with a native plant fertiliser or well-rotted cow manure rather than a general mix. Gardening Australia says an annual prune keeps trees compact or even hedge-shaped, and grafted trees give the most reliable results. Rats chew into the nuts, and a fungal disease of the husk can make nuts drop before they mature.

• Tree pruning
• Tree removal
• Stump grinding