The macadamia tree comes to us from down under in the land of koalas and kangaroo, Queensland, Australia. It is botanically classified in the Proteaceae family which is a large genus containing proteas, leucdodendrons/grevillea, banksia, hakea and lots more.
The tree is evergreen and is flowering at this time of year with cascading stems of mini-flowers that when pollinated either by wind, birds or insects will set the hard shell fruit and the mature nuts that will be ready for harvesting next winter.
Macadamia trees are very adaptable and truly enjoy the full sunlight and well drained soils that we find on our slopes in North San Diego County.
You want to obtain grafted trees with varieties like Cate, Beaumont, and Elimbah which are good producers for this area. You will start seeing some fruits in a few years, but a good tree will produce 30-50 pounds of nuts at 10 years of age and will increase gradually for many years.
A macadamia tree has about the same cold tolerance as avocados, lemons or limes and can withstand more heat than avocados in our inland valleys but not the hot deserts.
These trees can stay alive with little water, but for good nut production, the trees will respond to average watering like avocado trees. A balanced fertilizer applied twice a year is sufficient and I will alter my feedings with blood meal and fish emulsion not too high in nitrogen. Too much nitrogen results in chlorosis showing in the leaves.
One pest you must watch out for and be on guard for is the tree rat which can use its incisor teeth to gnaw through the incredibly hard shell, which always amazes me.
The edible fruit or flavorful kernel is wrapped in an outer husk which dries in a few days and splits open to reveal the nut which can be peeled off. Now the process of obtaining the delicious fruit inside the nut is the chore.
There are small hand operated crackers that will do a good job when pressure is applied to the handle of the cracker. A good old fashion hammer or the vice in the garage sometimes is used but can damage the soft tasty fruit inside.
There are so many wonderful healthy fruits from our locally grown trees but the macadamia nut, I must admit, is one of my favorites.
For more information, you may contact the California Macadamia Society at (760) 728-8081.
Roger Boddaert, Maker of Natural Gardens, can be reached at (760) 728-4297.