Macadamia nuts grow on trees. These sought-after nuts are native to Australia, originating in northeastern New South Wales and southeastern Queensland. Known for their rich, buttery flavor and unique texture, macadamia nuts have become a popular delicacy worldwide. Their cultivation has expanded to other subtropical regions, including Hawaii, South Africa, and parts of Central and South America. The process from a flowering tree to the edible nut results in a product valued for its taste and nutritional content.
The Macadamia Tree Explained
Macadamia trees (genus Macadamia) are evergreen trees in the Proteaceae family. They have glossy, dark green leaves and can grow large, reaching heights of 12 to 15 meters in mature specimens. The leaves are arranged in whorls of three to six, measuring 60 to 300 millimeters long. Macadamia trees are slow-growing, taking 4 to 5 years from planting to begin bearing fruit, and 10 to 15 years to reach full commercial production. A mature tree can produce nuts for over 50 to 100 years.
How Macadamia Nuts Develop
The development of a macadamia nut begins with the tree’s flowering stage, which occurs in early spring, from August to September in the Southern Hemisphere. Macadamia trees produce long, slender flower clusters called racemes, 50 to 300 millimeters in length. Each raceme holds between 100 to 300 small flowers that are white to pinkish-white and sweetly fragrant. Only less than 5% of these flowers will develop into mature nuts, with some racemes yielding up to 15 ‘nutlets’.
Following pollination, the base of the flower swells, forming a small, green fruit. This fruit consists of a fibrous outer husk that encases a hard, woody shell. The edible kernel, which is the macadamia nut we consume, is the seed found inside this hard shell. The nuts develop and accumulate oil, with shell hardening in December and oil accumulation from late December to January. The process from flowering to a mature nut takes six to seven months.
Harvesting the Tree-Grown Delicacy
Macadamia nuts are typically harvested once they naturally mature and fall from the tree. This natural drop occurs between March and September, depending on the region and variety. Farmers prepare the ground beneath the trees by mowing to facilitate collection. The nuts are gathered from the orchard floor by hand or using specialized harvesting machines.
After collection, the fibrous green outer husk must be removed. This dehusking process is performed within 24 hours of harvest to prevent mold and ensure kernel quality. The husk, which protects the inner hard shell, is removed by machines that squeeze it off, leaving the hard shell intact. The de-husked nuts, still in their shells, are prepared for further processing, including drying and cracking to reveal the edible kernel.