Macadamia Nuts

Revised January 2024


The macadamia nut tree is a fast-growing, medium-sized evergreen tree with heavy, dark green foliage that hails from Australia. Its leaves – which are blunt tipped, oblong, and generally a foot or more longer – develop in either whorls of twos, threes, or fours, but are rarely solitary. Macadamia flowers are small and whitish, hassled and growing on long spikes, while its nuts can ripen throughout the year, though they primarily ripen in the fall and the spring. The nut has a leathery case that is 1 inch in diameter, containing either a spherical nut or two hemisphere nuts. They also have a smooth hard shell that encases a white kernel.

While macadamia nuts originate and are grown in Australia, commercial production is mainly in Hawaii. Some countries in Latin America, Africa, and Asia also grow macadamia nuts, while trees can be found in California and Florida for the continental United States.

The highest quality macadamia kernels are not only free of defects or insect and fungal damage, but also contain at least 72 percent oil. The kernels with less than 72 percent oil are usually immature and harder and will over-brown when roasted.


Nearly all of the commercially grown U.S. macadamia nuts are produced in Hawaii. In 2022, there was 16,200 bearing acres of macadamia nuts producing a total of 37.7 million pounds (NASS 2022).

In Hawaii, commercial macadamia nut orchards are planted with grafted seedlings. Generally, the trees are at their most vulnerable during the first four years after tree establishment, after which the rows can grow together for a continuous canopy that makes the trees less prone to damage. After that, trees are likely to bear a small crop in the fifth year after planting and will reach full production in 12 to 15 years. A good tree can produce macadamia nuts for 40 years.

Macadamia trees need a lot of management for profit and good nut quality. Because they are susceptible to many pests and diseases, they require regular monitoring and control measure applications. Orchard operations are also required to minimize environmental risk, due to increasing scrutiny, which means that issues such as noise pollution from de-husking, spray drift control, and soil erosion from high rainfall, shade, and mechanical harvesting need to be addressed.

In addition to providing the nuts for harvest, macadamia trees can also help to generate honey production for nearby beehives. Sheep also can be used as natural lawn mowers to reduce the costs of herbicides and weeding, decreasing the risk of chemical toxicity in the soil and providing additional income with wool products.


Macadamia nuts are harvested manually after falling, which occurs for eight to nine months of the year in Hawaii (July to March). On relatively even land, large-scale producers use mechanical sweepers and pickup devices to offset the high cost of agricultural labor. To prevent losses from mold, germination, and animal damage, macadamia nuts should be harvested at least every four weeks during rainy weather, though they don’t need to be harvested as frequently during dry weather.

Unhusked nuts should not be stored for more than a day. Rather, it is best to husk the nuts immediately and either air dry them or take them to the processor the next day. In cases where the nuts were picked and cannot be husked or deliver to the processor, the in-husk nuts should be dried, by spreading them on a wire or slotted rack that is out of the rain and in direct sunlight.


There are no regulations or restrictions in the market of macadamia nuts, so the prices are determined by supply and demand market forces. The largest markets for macadamia nuts exported from South Africa are the United States, Europe, and Asia.

Macadamia nuts can be used for confectionary, baking, ice cream, and snack food industries. Because of the oil’s rich, cushiony skin feel and high oxidative stability, it is also suitable for heavy creams and skin care formulas. Research has shown that macadamia nut consumption may significantly lower heart disease risk.

The kernel, which is the main product of the macadamia nut tree, is oil or dry roasted after the husk is removed. Oil that is extracted from the culled nuts is commonly used in soaps, sunscreens, and shampoos, while the remaining press cake can be used in animal feed. 

While the kernel and oil are the main products of macadamia nuts, both the shells and the husks also have uses. Macadamia shells can be used as mulch, as fuel in macadamia nut processing, as a planting medium for anthurium cultures (flowering plants native to tropical America), for plastic manufacture, or as a sand substitute for sandblasting. Macadamia husks can be used as mulch or compost for fertilizer.


Hawaii Macadamia Nut Association
Macadamia Crop Information
Macadamia Market Value Chain

Noncitrus Fruits and Nuts, National Agricultural Statistical Service (NASS), USDA