Macadamia nut trees are native to tropical rain forests. Because of this, to be successful in growing the macadamia nut tree, try to mimic its native environment by giving it dappled shade and lots of moisture. While the tree will do fine in direct sun, it will need protection from the hotter rays in the afternoon in very warm regions. If all goes well, and your macadamia nut tree blooms, you will have nuts to harvest in October and November. While there are many varieties of macadamia nut trees, the best for Florida gardeners are Beaumont and Vista Hybrid. In Central and Northern Florida, consider Waimanalo M. integrifolia, which can tolerate cooler climates.
Check the soil pH around the macadamia nut tree. While the tree is tolerant of a wide range of soil textures, it does best in soil with a pH of 5.5 to 6.5. To change the pH you will need to add amendments to the soil. Your Florida county extension agent can help you determine which amendments are best for the area in your county.
Apply a 6-inch layer of mulch, in a 3-foot radius around the base of the tree. This will help to keep the soil moist and cool in the hot Florida sun.
Fertilize your macadamia nut tree carefully. In Florida, 6-6-6 tree spikes work well. This tree does not tolerate potash, so check the label of products you are considering purchasing.
Water the macadamia nut tree regularly and deeply. How much water you supply depends upon the type of soil in which the tree is planted, and the air temperature. Florida is generally more humid, but during hot, drier than normal periods, supply the tree with more water. It's best not to let the tree dry out any deeper than the top 2 inches of soil.
Frost in Florida is rare, but can happen. Protect your macadamia nut tree from frost by covering it with a tarp or blanket. As the tree matures, it will build some tolerance to frost but will still need protection.
Harvest the macadamia nuts when they fall to the ground.