What Is Macadamia Nuts?
Macadamia is a genus of four species of trees in the flowering plant family Proteaceae.They are indigenous to Australia, native to northeastern New South Wales and central and southeastern Queensland specifically. Two species of the genus are commercially important for their fruit, the macadamia nut (or simply macadamia). Global production in 2015 was 160,000 tonnes (180,000 short tons).Other names include Queensland nut, bush nut, maroochi nut, bauple nut and Hawaii nut.In Australian Aboriginal languages, the fruit is known by names such as bauple, gyndl or jindilli (north of Great Dividing Range) and boombera (south of the Great Range).It was an important source of bushfood for the Aboriginal peoples who are the original inhabitants of the area.
The Description Of A Macadamia Nut
The leaves are arranged in whorls of three to six, lanceolate to obovate or elliptic in shape, 60–300 mm (2+1⁄2–12 in) long and 30–130 mm (1+1⁄8–5+1⁄8 in) broad, with an entire or spiny-serrated margin. The flowers are produced in a long, slender, simple raceme 50–300 mm (2–12 in) long, the individual flowers 10–15 mm (3⁄8–9⁄16 in) long, white to pink or purple, with four tepals. The fruit is a hard, woody, globose follicle with a pointed apex, containing one or two seeds. The nutshell (“coat”) is particularly tough and requires around 2000 N to crack. The shell material is five times harder than hazelnut shells and has mechanical properties similar to aluminum. It has a Vickers hardness of 35.
Production Of Macadamia Nuts
In 2018, South Africa was estimated as the leading producer of macadamia nuts, with 54,000 tonnes out of global production of 211,000 tonnes.Macadamia is commercially produced in many countries of Southeast Asia, South America, Australia, and North America having Mediterranean, temperate or tropical climates.
How To Grow Macadamia Nuts In South Africa
- Prepare the soil prior to planting with compost and decomposed manure.
- Plant at the same height as it was in the pot, and backfill, pressing the soil down firmly.
- Water to remove any air pockets.
- Apply a layer of mulch around the tree to a diameter of around 1m.
- In cold climates, place 3–4 stakes around the tree and wrap in hessian during periods of frost for the first few years to help the tree establish. This also helps protect young trees from wind.
Caring For A Macadamia Tree
The macadamia is a shallow-rooted tree, so regular watering is required, especially during the first few years and in dry hot weather. Once established, water weekly from spring to autumn. Mulch to conserve soil moisture.
An Australian native related to banksia and grevillea, the macadamia is sensitive to some fertilisers. Always use a fertiliser designed specifically for native plants. Improve soil at planting time with compost and decomposed manure. Apply a slow-release native fertiliser in early spring, followed by liquid applications of fish and seaweed solutions periodically during summer to ensure the tree has ample nutrients while setting its crop.
How And When To Prune A Macadamia Tree
Regular pruning is not required. Instead, prune only when required to control shape or height.
Diseases and Pests
Depending on your climate, macadamia can be relatively pest-free. To protect it, encourage beneficial insects to the garden, such as parasitic wasps to prevent nut borers and weevils becoming a problem in tropical and sub-tropical areas. If you do get an infestation of pests, try Yates Success or Eco Neem.
