This page is split into two section
A – Questions about the macadamias
B – Questions about machines
A – Questions about macadamias
Q – How long before Macadamia trees produce nuts?
A – A grafted tree will usually start to produce in its 4th or 5th year after planting. You should have a reasonable crop after 7 or 8 years. A seedling tree will usually not produce nuts until it is 10 to 12 years old.
Q – What about tree maintenance?
A – Macadamias are a low maintenance tree and will grow in almost any soil type, as long as it is not water logged. It is a forest tree native to Queensland Australia and likes a good mulch. The main pest in NZ is the green vegetable bug, attacking the young nuts and causing black spots on the nut kernel. Long grass and seeds are known to harbour these bugs, keeping grass short or having it grazed by sheep and poultry will help.
More recently the guava moth has also become a problem pest with pheromone traps and spraying the only solution at the moment. Organic growers and the majority of smaller growers take the risk of loosing some of their crop, in a bad year up to 30% by not spraying. If you decide to spray, then 3 times a season will do the job, starting 3 weeks after flowering at intervals of about 3 weeks.
Q – Can macadamias be pruned?
A – Yes, but be aware there are 2 types of trees, Droppers and stickers and pruning varies for each type.
Macadamias will stand quite heavy pruning. The aim when pruning is to keep the tree to a manageable height (3 to 4 metres). Do this by cutting strong leaders out of a sticker type tree or pruning the outside of a dropper variety. This will open up the interior of the tree to light, air and bees to help with pollination, particularly because Macadamias tend to flower into the centre of the tree.
In short, keep the tree low and open on the inside to aid pollination and to make picking easier. Reduce multiple forks to a maximum of two to avoid the incidence of wind damage.
Q – When are macadamias ready for picking?
A – For varieties which do not drop their nuts (Such as Beaumont), the simplest way is to look at the lining of the husk after the shortest day of the year. When the lining has turned deep brown, to about the same colour as the nut inside, the crop is ready for picking. Depending on the weather and position of the trees this can be as late as one to two months past the shortest day. Beware, trees can drop (abort) quite a lot of nuts if stressed by drought, these nuts will be immature and can be mistaken as ripe.
Q – What to do after picking.
1 Remove the husks preferably within 24 to 48 hours of picking.
2 Bag the fresh nuts in 10kg onion sacks and hang them in an airy and shaded position (open carport is ideal), for a 3 month minimum. Hang them out of the reach of rats and mice who love chewing through them. During drying the nuts will loose about 15% of their weight.
Larger or Commercial growers will tend have a drying room with heat up to 35degC lots of air movement and dehumidifiers operating.
3 Once dry, store them on or near the hot water cylinder for a minimum of 3 weeks. The additional weight loss after this drying will be approximately 10% (a dehumidifier can be very helpful).
Larger growers will have dried them to below 3% moisture in their drying rooms ready for cracking as required.
4 Once fully dry and ready for cracking (less then 3% moisture) . The kernel will ideally be rattling in the shell and above all, will be crunchy and sweet.
WARNING – Rats love Macadamias!!! If you see empty shells with little holes chewed into it ….. You know you have them!
Q – Do macadamias keep well?
A – All nuts deteriorate over time, however macadamias ‘in shell’ will keep well for a couple of years in a dark, cool and airy place. After cracking, the kernels will keep for about six months if kept in an airtight and moisture proof container.
larger growers will vacuum seal kernels or Nitrogen purge and pressure seal bags to keep the kernels fresh for a considerable time.
If you have any other questions about our machines or macadamia growing please give us a call or email and we will do our best to help.
ilko Scheepens
Owner and Engineer
