By Ralph E. Mitchell

I was out in our Demonstration Garden at the East Port Campus on Harbor View Road in Port Charlotte this morning and smelled a floral fragrance of some type –a honey-like scent. I followed my nose to our macadamia tree which was in full bloom! We try all different types of trees and shrubs at this Demonstration Garden – most are successful…some get composted. Our macadamia tree has been in the garden a few years and is doing great – it has even produced a few nuts! The macadamia is a beautiful evergreen tree that can be grown in many parts of Charlotte County. Originally from Australia and then introduced to Hawaii where it really took root, the macadamia can also be grown in California and Florida.

Growing up to forty feet tall, macadamia trees have eight inch long leaves with small spines along the margin edges. The sweet-scented flowers are white to pink and hang in long racemes over six inches long. The nut develops within a green husk that eventually opens up to reveal a hard nut. Once cracked, a white kernel is exposed which, when roasted, provides one of the best nuts known. There are a couple of macadamia species (including hybrids) available. Commonly called either “smooth shell” (Macadamia integrifolia) or “rough shelled” (Macadamia tetraphylla), macadamias, there are many named cultivars including Hawaiian and California varieties. ‘Beaumont’ is a noted variety that is good for backyard plantings. While seeds can be sprouted, it will take upwards to twelve years to produce a crop. Therefore, it is best to obtain grafted varieties which will begin to produce in as little as two to five years. In perfect situations, a mature tree could produce upwards of one-hundred and fifty pounds of nuts in the shell. This of course does not take into account the realities of pesky squirrels and rats. Expect the nuts to be ripe anywhere from July through November. Ripe nuts will fall to ground. As the nuts dry, you will notice that the husk will split open exposing the nut inside. The nuts are mechanically cracked, allowed to dry and then roasted at two-hundred and seventy-five degrees Fahrenheit either dry roasted or with some refined coconut oil for twelve to fifteen minutes.

Macadamias do best in full sun and in well-drained soil. While they can survive in our subtropical climate, mature trees can tolerate temperatures as low as twenty-five degrees Fahrenheit. Young trees need protection as they can be killed by freezing temperatures. Once established, macadamia are fairly drought-tolerant but will appreciate irrigation during flowering and fruiting. Fertilize with a citrus-type fertilizer as per label directions.

Macadamia nut trees are not without their challenges. However, as many gardeners could agree, new additions – even the macadamia – could make an interesting and potentially tasty addition to your landscape! For more information on all types of subtropical edible plants suitable for our area, please call our Master Gardener volunteers on the Plant Lifeline on Mondays, Wednesdays and Fridays from 1 to 4 pm at 764-4340 for gardening help and insight into their role as an Extension volunteer. Don’t forget to visit our other County Plant Clinics in the area. Please check this link for a complete list of site locations, dates and times – https://blogs.ifas.ufl.edu/charlotteco/files/2018/03/Plant-Clinics-Schedule.pdf. Ralph E. Mitchell is the Director/Horticulture Agent for the Charlotte County Extension Service. He can be reached at 941-764-4344 or ralph.mitchell@charlottecountyfl.gov.

Resources:
Malo, S. E. & Campbell, C. W. (2009) The Macadamia. The University of Florida Extension Service, IFAS.
California Rare Fruit Growers, Inc. (1997) Macadamia. http://www.crfg.org/pubs/ff/macadamia.html .

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