Troubleshooting
Rough-Shelled Macadamia problems — and how to fix them
Rough-Shelled Macadamia (Macadamia tetraphylla) is generally forgiving once you match its basics, but a few issues come up again and again. Here is what each one looks like, why it happens, and the fix.
Frost sensitivity when young
Though hardier than M. integrifolia, young trees are still frost-tender. Protect from hard frost and cold wind until well established.
Phosphorus toxicity
High-phosphorus fertilisers scorch and yellow the leaves by damaging proteoid roots. Always feed with low-P, Proteaceae-suitable products.
Prickly juvenile foliage
Young leaves are spiny and awkward to handle; this is normal and softens as the tree matures. Wear gloves when pruning young plants.
Variable nut quality and biennial bearing
Seedlings vary widely in shell thickness and oil content and crop unevenly. Grow named grafted cultivars and keep moisture and feeding steady.
Prevent rough-shelled macadamia problems before they start
Most rough-shelled macadamia issues are care-mismatch, not bad luck. Dial in the basics:
Looking for rough-shelled macadamia in general rather than its problems? Read the full rough-shelled macadamia care guide — light, water, soil and feeding.
Rough-Shelled Macadamia problems — FAQ
Why is my rough-shelled macadamia frost sensitivity when young?
Though hardier than M. integrifolia, young trees are still frost-tender. Protect from hard frost and cold wind until well established.
Why is my rough-shelled macadamia phosphorus toxicity?
High-phosphorus fertilisers scorch and yellow the leaves by damaging proteoid roots. Always feed with low-P, Proteaceae-suitable products.
Why is my rough-shelled macadamia prickly juvenile foliage?
Young leaves are spiny and awkward to handle; this is normal and softens as the tree matures. Wear gloves when pruning young plants.
Why is my rough-shelled macadamia variable nut quality and biennial bearing?
Seedlings vary widely in shell thickness and oil content and crop unevenly. Grow named grafted cultivars and keep moisture and feeding steady.