Macadamia Nut

Propagation
In Hawaii, commercial orchards are usually planted from grafted seedlings. Macadamia trees begin to produce small amounts of fruit in the fifth year after planting, and reach full production in 12 to 15 years.

Soil Type and Location
Macadamia trees can be grown in deep, well-drained soils with a pH of 5.0-6.5 or in well-drained a'a lava fields that are weathered enough to support natural vegetation. The tree requires 60-120 inches of rainfall per year and can grow at altitudes from sea level to 2,500 feet.

Cultural Practices
Yields can be increased through cross-pollination. Beehives near the orchard can generate additional income through honey production. Another possibility is the integration of animals.
Intercropping macadamia with faster-fruiting crops is one way to get an early return. In Kona on the Big Island of Hawaii, coffee is sometimes planted between macadamia trees. Another approach is to increase the initial planting density to get a higher overall yield early on.

Fertilization
Leaf tissue analysis is recommended semi-annually to determine the best way to fertilize your orchard and prevent nutritional problems. If you have never collected leaf or soil samples, consult an extension agent or fertilizer representative before you begin. If your orchard looks normal, a sample of one tree per acre is sufficient. Collect leaf samples before the trees have new leaves, usually during February and March, or before fertilizing in September or October. Select three to four branches with the top buds just opening and beginning to grow. Do not select branches with long, hard red scales (called false blush) on the buds. These scales will not open for several months. At the proper growth stage, the buds will develop three small, pale green leaves that look like claws. Pick a healthy leaf from the second leaf node (whorl) below the bud. Fifteen leaves from four to five trees are required for each sample submitted for analysis. The sample should be placed in a plastic bag and labeled with your name, the date of sampling, and the sample number.

Harvesting
Macadamia nuts need to be hand-harvested after they drop. In Hawaii, nuts typically drop 8-9 months out of the year (July to March). Large producers also use mechanical sweepers and picking equipment on relatively flat land to offset Hawaii's high agricultural labor costs.

Postharvest
Never store unshelled nuts in bags or boxes for more than a day. It is best to shell and air dry immediately or send to a processing plant the next day. If the nuts cannot be shelled or sent to a processing plant after they are picked, the nuts should be dried in the shell. The nuts in the shell should be spread on wire or slotted racks to avoid rain and direct sunlight.