Macadamia trees are indigenous to Australia and are generally grown for the macadamia nut which are a rich source of essential nutrients (20% or more) including thiamine, manganese, iron, magnesium and phosphorus.
Compared with other edible nuts, such as almonds and cashews, macadamias are high in total fat and relatively low in protein.
The flowers are 5–10mm long and are born on racemes with 100–150 flowers. Each flower has 20 ovules, four anthers attached to the petals, and a long stigma. It takes about a week for all the flowers on a raceme to open, with most opening over 2 days.
In Australia, macadamia will start flowering in August and September. The flowers produce both pollen and nectar which attracts bees.
Some commercial beekeepers place their bee hives on Macadamia farms to produce Macadamia Honey in exchange to allow their bees to pollinate the flowers to produce the Macadamia nut. It has been estimated that about 150 bee visits to a racemes are needed for full pollination in Australia.
Macadamias are suited to large gardens as the evergreen trees grow to 20m in height. They generally thrive in tropical and subtropical climates, but they will also grow well in frost-free, warm-temperate areas.
Plant young trees in full sun and protect them from strong winds. Ensure the soil is moist, well drained and enriched with organic matter prior to planting. In spring and summer, feed with a complete fertiliser and water in well. Trees will also benefit from a fortnightly liquid feed during the growing season.