How to grow Macadamia Nuts

An easy-to-follow guide to growing your own Macadamia Nuts. Includes tips on keeping the trees healthy, harvesting and more!

Like most nut trees, Macadamia Nuts require deep, well draining soil. They will not tolerate waterlogged soil and will develop root rot as a result. Avoid planting in heavy clay unless the soil has been amended. Heavy soils can be improved by incorporating gypsum and well rotted organic matter, and mounding by the soil before planting to improve drainage. 

Macadamia Nut trees require a location that receives full sun, but is sheltered from strong winds. 

No, Macadamia Nut trees are not frost tolerant. Young trees will be killed by temperatures of -6°C (21°F). Mature trees can tolerate some light frost, however do best in frost free locations.  

Plant Macadamia trees roughly 8m apart. Plant spacing also depends on your pruning method.  

Macadamia trees will grow optimally in areas where the average annual temperatures are between 20 and 25°C (68–77°F)

Late autumn or early spring is the best time to transplant most dormant plants. However, if transplant in the heat of summer, you'll need to be diligent in watering and provide extra shade for your plant in the first few weeks after transplanting. 

Dig a hole 2-3 times the width of the root ball. The hole should allow the plant to sit at the same level in the soil as it was previously. Fill the hole with soil ensuring the crown of the plant, where roots and stem meet, is level with the soil surface. 

Plant out in the early morning or evening and/or on an overcast day. Avoid planting at peak sun times or on windy days, this will allow your plants to settle in comfortably and protect them from windburn and sunburn.  

Macadamia trees are usually fed twice a year, in autumn and spring. 

Top-dress the soil around the tree with well-rotted organic matter such as compost, cow or horse manure. You can also apply an organic fertiliser.  

Add a 2-3 inch layer of mulch around the tree up to the drip line to retain moisture (be careful not to pile mulch against the tree trunk as this may lead to trunk rot and disease). 

Macadamia nuts will fall to the ground when they are mature. Harvest the nuts regularly. You can also pick macadamia nuts off the tree when their skin begins to crack. Remove the outer green hulls within 24 hours of harvest to prevent mildew from growing. 

Pests that affect Macadamia trees include: Macadamia Flower Caterpillar, Lace Bug, Macadamia Felted Coccid, Macadamia Twig Girdler, Green Stink Bug, Sigastus Weevil, Fruit Spotting Bug, Macadamia Nut Borer, Flower Thrips, Scale, Macadamia Leaf Miner, Macadamia Kernel Grub, Rats, Dark Beetle, Aphids, Pinhole Borer, Cicada. 

Diseases that affect Macadamia trees include: Anthracnose, Husk Spot, Raceme Blight, Slow and Quick Tree Decline, Phytophthora Stem Trunk and Stem Canker, Armillaria Root Rot, Branch Dieback Disease, Bacterial Wilt, Algal Leaf Spot, Vining Disorder, Botrytis Blight, Phomopsis Husk Rot. 

Macadamia trees do not require pruning to flower or bear nuts, however regular pruning is a great way to manage the size of your tree. If left unpruned Macadamia trees can grow up to 10m tall.

At the end of the season, you can prune the tree in order to remove old or unproductive wood. Open up the center to let light and air in by removing any overlapping branches, this will help to prevent disease.