Macadamia is a native Australian tree that produces the only commercially significant nut indigenous to Australia. It is commercially grown in coastal Queensland and northern NSW but is suitable for home gardens across subtropical and warm temperate regions. Tracked varieties include A4 (a high-yielding variety with excellent nut quality, widely used in commercial orchards), A16 (another commercial standard with good cracking characteristics), and Gouros (a productive variety suited to both commercial and home garden production). Macadamia trees prefer a subtropical climate with warm summers and mild winters. They are sensitive to frost when young but become hardier with age. Plant in well-drained, slightly acidic soil (pH 5.5-6.5) in full sun. Macadamias have proteoid roots that are sensitive to phosphorus; use low-phosphorus fertilisers specifically formulated for Australian native plants. Trees begin producing nuts from 4-6 years of age, with full production from 10-12 years. Nuts fall naturally when ripe from autumn to spring. In WA, macadamia is grown in the southern coastal regions and in Gingin. No significant quarantine restrictions apply. The main pest in Australia is the macadamia felted coccid; monitor and treat with approved sprays as required. Macadamia twig girdler can also cause stem dieback.