What goes through harvesting and storing the world’s priciest nut? There are two types of edible macadamia. The smooth shelled Queensland nut, M. intergrifolia, and rough shelled nut M. tetraphylla that are native to Australia.
Macadamia is a glossy evergreen with leaves that resemble holly, flowers that range from pink to white and edible nuts that ripen at random. They thrive in moist areas and rainforests. They grow in USDA Hardiness Zones 9 to 11.
A self-pollinating tree does not produce true seeds. It may take more than 10 years for the tree to mature. It may or may not set fruit. Most people opt for grafts and cut the maturity time in half. They live up to 40 or 60 years. They begin set fruits at 6 or 7 years. At 10 years, they have reached maturity.
They produce approximately 30- 50 pounds yields (14-23 kilogrammes). This gradually increases through the cultivars lifetime. It take 4 to 5years for a tree to bear nuts, then 8 months for the nuts to ripen. When it’s time to harvest, you can test or check for ripeness using a couple of methods.
First, you can touch the outsides. The dry ones are ripe while the sticky ones are not yet ripe.
The second test is checking the colour inside the husks. The white ones are definitely unripe. Check for chocolate brown ones.
The last test is using water. The unripe kernels sink to the bottom of the bucket while ripe ones float on the surface. Not all blossoms bear nuts. However, those that do witness husks drying out. They lose tackiness and turn from green to brown.
They shrink and split open. Split edges turn brown and the brown nut inside becomes visible.
Some varieties like “Cate, James and Vista” self-harvest. I.e. they drop ripe fruit to the ground for easy retrieval. Some people opt to leave a tarp under these trees to catch the nuts. It poses some disadvantages. That is, it impedes water penetration to the roots.
In addition, it can gather rainwater. Nuts falling inside will either rot or decay. The tarp damages the lawn or garden. It is more advisable to visit the tree daily to collect the nuts. Ensure to collect all the fruit. It will keep rodents away.
Once gathered remove the husks and evaluate the shells. Discard the mouldy ones and any that have been damaged.
For cultivars that do not self-harvest, i.e. they require one to gather the fruits from the tree by hand. They do drop to the ground just not at the same time.
To harvest them, place a tarp and use a long pole to tap branches. Remove the husks immediately after harvesting.
You can invest in any number of tools that aid in collection of nuts. They can be found at local store or online.
For example, a push harvester that collects using a removable basket. It definitely reduces the amount of time spent bending over.
Watch out for diseases during nut collection. Some signs to look out for include spots on leaves, twig dieback or bronzed yellow leaves.
The most common diseases that affect macadamia include macadamia root rot and trunk canker. Prolonged drought or poor drainage are the main causes. Macadamia quick decline is another disease. This one is caused by stress such as low pH, or nutritional problems.
How do I preserve them macadamia after I harvest them? Post-harvest, proper preservation and storage are essential to protect your crop from spoiling and going to waste before you use it.
After removing the outer husks, place the nuts on a screen no more than two deep. Air dry for two to three weeks in a cool, dry location. This will loosen kernels from their shells. Use a vise or a specialty nutcracker to crack the shells and remove the kernels. Dry the kernels in a food dehydrator or in the oven at 1000° F.
After about two days. Do not rush the drying process. When they are crisp to bite, they are ready. Keep an eye on them so they do not burn, shelled nuts will keep for a year as long as they are protected from heat and light. Keep them in tightly closed containers for some months. Frozen, shelled or unshelled nuts will last up to 2 years.