Varieties of Macadamia Nuts

• There are two basic varieties of macadamia nut trees: Macadamia Intergrifolia and Macadamia tetraphylla. There are many sub-varieties from the two, including Beaumont, Louisa, Cates and James. They originated in southeastern Queensland where they grow in rain forests and along stream banks.
  
  Here in the United States, Hawaii and California are the leading growers of macadamia nuts. You can tell the two varieties apart by their leaves and flowers. The M. intergrifolia leaves come in threes, are pale green and grow from 8 to 11 inches long. Their flowers are creamy white clusters that are 6 to 12 inches long. The M. tetraphyllas leaves come in fours, are bronzy pink and may be as large as 20 inches long. The flowers are cream or pink and come in clusters up to 15 inches long. The M. tetraphyllas are used more in a home garden and have a slightly higher content of sugar making them a delicious treat for roasting or using in recipes. Macadamia trees can be grown from seeds also, but it will take 8 to 12 years to actually grow the nuts.
  
  

Growing Macadamia Trees

• Location and irrigation are most important to these types of trees. Macadamias grow best in full sun. In very hot tropical climates, some shade is needed part of the day. The branches are small and the nuts can get very heavy, therefore protection from strong winds is essential. The trees grow best in a low pH and salt content soil. However they will grow in almost any soil as long as it is well drained. Macadamias require a lot of water as young trees and while the nuts are growing on the trees. They should be watered deep during those times. Watering deep means to water them for longer periods of time so the water can saturate deep into the soil.
  
  You can purchase young trees once you pick your location. Plant them by adding some peat and compost to the soil for drainage and nutrients. The top of the root ball should be just above ground level and the roots should be spread apart a bit it they were tied up in canvas. Six months after planting the trees should have a fertilizer placed on them such as a citrus mix. They do not require much nitrogen, so when buying fertilizer make sure you get one with no more than 1 percent. You will need to protect the trees if there is a light frost. Plastic sheeting can be placed over the small trees during these times.
  
  

Caring for Adult Trees

• At least twice a year, 5 lbs. of a citrus fertilizer should be applied to the soil around the trees. They will require less water during the dormant season, but will still require deep watering while producing the nuts. Pruning is essential, but must be done a little at a time. Although heavy pruning will probably not kill the tree, it will reduce the amount of nuts you get. Prune the tree so there is one main stem. Keep dead wood trimmed off and take it away from the tree. Leaving dead wood sit around the tree is an invitation for bugs and mildew. Macadamias in the United States are resistant to bugs and disease. Do not use chemicals on the trees unless you actually see something. You can purchase insecticides and anti-fungal chemicals at hardware, home improvement stores and your local nursery.