Native to Australia and found growing naturally in rainforests and along stream banks. Thou the Aborigines did not seem to utilise as a food source. First discovered in eastern Australia and it was named after Dr John Macadam. Cultivation first occurred 1870 with a seedling orchard was planted in New South Wales. Largest commercial orchard was developed in Hawaii. First introduced to New Zealand at Kerikeri 1932. Belongs to the Protaceae family – also includes Protea, Grevillea, Banksia, Leucadendron and Rewarewa.
An upright handsome evergreen tree with exotic appearance. A great addition for the nut grove. Left unpruned can reach 15-20m tall. Leaves are serrated along margins and are in whorls of four at nodes.
Rich in vegetable protein, very high in good oil, high in selenium – element often scarce in New Zealand soils which is good for male fertility. No Cholesterol but can reduce blood cholesterol if eaten regularly each week. Excellent snack food.
How to Eat
Delicious raw, roasted, seasoned, dipped in chocolate or used in sweet or savoury cooking. Dry roasted: Low oven (110°-120°C); put macadamias in oven dish for 7 minutes. Stir and turn and cook for another 7 minutes. Whole kernels will take longer than halves or pieces so adjust accordingly. Remember they will keep cooking once removed from oven.
On a mature tree you can expect about 13-25kg of nuts per tree.
Generic Fruiting Time
Shelter from strong winds.
Young trees need protection from frosts. Then they can handle down to -3°C. Wrapping trunks in cardboard or foil will help protect for first five years. General rule – will thrive where citrus grows well. Warm, sub-tropical conditions.
Prone to root rot, do not like wet soils though quite resistant to drought so a well drained soil is required. Moisture stress can result in fruit drop. Water regularly and deeply during dry periods. Will handle a wide range of soil types from heavy to sandy.
Macadamias have a tap root which should not be disturbed when planting, stake for support, they are top heavy for first few years. Mulch to help retain moisture and reduce weeds.
If over fertilised there will be lots of growth and not many nuts will be produced. Mulch with grass and husks from the nuts. Can spray with seaweed foliage spray but do not apply lime. Citrus fertiliser can be applied if needed.
Keep to a single truck. First branches appear about 1m high. Young trees are brittle. Early pruning to avoid narrow branch crutch angles will help develop a strong structure reducing the chance of fork breakages. After 6 years the tree frame will be stable so the shelter can be reduced or removed to let light in. As the tree gets older it is important to keep canopy open and light. Once mature take out centre and try to keep height to 3-3.5m tall. Remove dead and damaged branches.
Green Vegetable bug can attack at the early nut stage, but is not noticed until nut is mature and there are little black craters in the kernel. Also leaf roller can be a problem. Regular mowing to keep grass and weeds under control. Watch for Lemonwood borer, remove and paint any cuts. Rats love Macadamias. Baiting is the best solution. They bore little holes in the shell to get into the kernel.