Subtropical macadamia nuts originated in Australia, but production has expanded to a number of suitable regions to satisfy rising global demand for mac nutmeat and oil. Young trees require about ten years to achieve commercial yields and then may continue to produce nuts for decades. Harvesting macadamias is more challenging than other nut crops because macs mature at different rates from tree to tree, making machine harvesting less effective. Growers usually just wait for the ripe nuts to fall and then rake them up.
Australia is a major producer and exports about 70 percent of its crop, although production last year dropped to around 44,000 MT because of damage from Cyclone Debbie and excessive rainfall. South Africa’s aggressive planting campaign pushed it into first place; SA harvested 54,000 MT in 2017, according to the International Macadamia Symposium. China buys about 40 percent of SA’s crop. Kenya is another top producer.
The U.S. produces around 20,000 MT per year and imports about 9,000 MT. Hawaii grows nearly all the U.S. supply of macadamia nuts, but acreage expansion is limited by land availability. In fact, bearing acreage sharply decreased between 2005 and 2006 before increasing a bit in 2013. Growers may plant other crops, such as coffee, between the trees to maximize land use and profit.
California began planting macs over 50 years ago in response to root rot among its avocado trees, but even varieties that can withstand light frosts are a challenging crop for the Golden State because macadamias require hand harvesting and hate hot Valley weather, meaning that expensive coastal land goes hand in hand with higher labor costs. Limited production is concentrated around San Diego, Ventura, and Santa Barbara.
So, Florida. Growers in the state would love to find a high value crop to offset losses from citrus. Macadamias are not an entirely easy fit, however, because of the potential for freezes during February bloom and high summer temps. Growers in central and southern Florida are experimenting with mac varieties that can tolerate some cold and are devising strategies to protect the trees from hot weather, such as dusting leaves with kaolin clay. The University of Florida is cheering the effort toward commercialization, and in May hosted a field day to promote macs to new growers. Maybe one day Florida will be the top U.S. producer!
U.S. imports of shelled macadamia nuts