Growing Macadamias in the Home Garden

macadamia packets.pngI’m eating my way through a packet of dry roasted and salted macadamias as I tap out this story on the keyboard and I’m having a hard time getting on with it because their SOOO delicious! Macadamias are my absolute favourite nuts to eat, so when I heard that a visit to a macadamia farm was included in my recent Food Trail Tour of the Atherton Tablelands in Tropical North Queensland, I was chuffed.

We arrived at Greg and Wendy O’Neill’s farm aptly named Wondaree Macadamia Nuts (I’m informed that Wondaree is a word used by North Queensland Aborigines meaning “trees”). The scene is lush and inviting but another tropical downpour is looming heavily upon us.

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Farmer Greg jumps on the bus with us to give us the “good oil” (literally) on growing macadamias. I notice the bee hive at the entrance to the farm used for pollination and no doubt some honey too. Greg notices I’m writing on my notepad as he speaks; he is warily cautious and jokingly threatens that anyone taking notes won’t be allowed to leave the farm alive. I explain who I am and that I’m in town with the Australian Institute of Horticulture then I boldly ask if he has any tips for the home gardener. Realizing I’m not out to steal his secrets for commercial production, he relaxes and is very forthcoming with some tips and pointers for us home gardeners.

I’m immediately taken with his approach to farming and even more so as he goes into his strategies for Integrated Pest Management. He’s a kindred spirit …. I knew it as soon as he mentioned the field we passed on the way in was being used for experimenting with improved pasture and cattle.

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Although the macadamia tree can grow to 20 metres (60 feet) high, with careful yearly pruning they can be limited in size, making them a good choice as a productive shade tree for a reasonable sized home garden. They are vulnerable to frost so cultivation would only suit frost free temperate to tropical zones. You will need rich well drained soil for best results. A good supply of nitrogen and potassium are needed to produce quality fruit. Addition of chicken manure and compost before planting and as a regular side dressing throughout the growing season is recommended. Being an Australian native plant it has adapted to low levels of phosphorus so be careful using any fertilisers high in phosphorus.

Greg points out that the Macadamia tree has a very fine fibrous root system that is vulnerable to drying out, so tip number one is to grow it with regular irrigation and a good layer of mulch in the home garden. Lucerne is a good mulch that adds nitrogen as it breaks down; a layer at least 5cm (2 inches) deep is needed around the drip line of the tree to keep moisture in and weeds out.

Keeping the weeds from competing for water and nutrients is essential for increased vitality of the tree and to maximize crops. This is particularly important from the time the tree is in flower until the full oil production is reached in the fruit/nut. Oil production in the fruit will take up to 3 months after initial fruit has been set.

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During this fruit development time, Greg keeps a keen eye on the available nutrients taken up by the trees. He does this through regular leaf testing which indicates any deficiencies that might affect the fruit. To remedy any deficiency, regular foliar sprays are applied to the orchard. So tip number 2 for the home gardener is a fortnightly liquid feed of worm juice and fish emulsion. Mix in some seaweed solution to help stimulate growth and protect against pests at the same time. A liquid feed will provide some additional nutrients while the tree is in its most active stage and avoid any deficiencies that could potentially affect the developing fruit.

I ask Greg about pest and disease problems that he encounters on the farm. He admits that they do have some problems with nut borer and weevils. Their practices have changed over the years with the current trend involving Integrated Pest Management. Greg explains that they use organic techniques as much as possible without aiming for certification. Previous routine spraying with insecticides has now been replaced with biological methods, introducing native parasitic wasps to help control many pests naturally. The new economics showed that the financial cost of spraying actually proved to be more than the cost of any crop lost using the new biological controls.

Tip number 3 for the home gardener is to encourage beneficial insects into the garden through companion planting, using lots of flowers that attract parasitic wasps in particular. Wait for the predators to come before resorting to chemical warfare. Growing companion plants that add nitrogen around the trees is also beneficial for plant growth.

A macadamia tree is an investment, as are many fruit and nut trees, taking 5 years after planting a grafted specimen before the tree produces a significant crop. It is considered “mature” only after 10 to 15 years.

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The old-fashioned harvesting roller is demonstrated with our tour group, picking up the green nuts that have fallen to the ground. The nuts will fall naturally when they have matured. The husk is still green to brown and encases the nut inside. On the farm they are harvested using machinery but can be collected by hand in the home garden as they fall off the tree. The husks on the farm are cracked to obtain the nuts then the husk is processed and returned as mulch under the trees. It’s a good display of closing the system.

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The nut is graded according to size and then cracked open again to reveal the small kernel inside that we eat. Plant breeding has increased the size of kernel weight from 15 percent to 50 percent now in some of the modern cultivars, which means much bigger macadamias for us to eat.

Now the fun starts … taste testing!

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Macadamias.pngWondaree Macadamia Nuts offer a range of flavored products, from natural raw or lightly salted macadamias to the tasty hickory smoked nuts.

Macadamias contain no cholesterol as they are a natural plant food. They are not genetically modified and only contain natural genes. Macadamias do not contain any trans fatty acids. Research has shown that macadamias can help lower blood cholesterol levels and may reduce the incidence of heart disease. They’re high in fibre, very high proportion of monounsaturated fat, contain no cholesterol, contain vitamins, minerals and protein essential in a healthy diet ….

AND they taste great, too!

  1. What a fantastic article! macadamias have always been my favourite nut and I have fond memories of childhood neighbours giving us bags of them from their home tree. Another must-have plant for my home garden in the future :D

  2. admin says:

    Good memories. Keep dreaming about and planning for that future garden.

  3. Mohammad Hoss says:

    May I have the contact details of a good nursery who can provide me with certified grafts/trees of macadamia?

    Thank you.
    00 961 70 333 659

  4. Bev wilkins says:

    Can you tell us when and how much can we prune our macadamia tree, it seems to be getting leggy after the prolonged dry spell we have had, it is about 6years old and we had a great crop last year.

  5. admin says:

    Best practice is to prune after harvest and just to maintain the shape. Better to give it a light prune every other year than leave it to get leggy.

  6. Oman says:

    I would like to start growing macadamias in the UK. Please can you let me know where i can buy seeds or can i use a raw nut?

    Thank you.

  7. admin says:

    I’m not sure about suppliers in the UK, but you could try contacting Greg at http://www.wondaree.com.au/ and see what he suggests.

  8. Justin says:

    I currently have 5 macadamia trees still about a foot high grown from seed. Could you please tell me when would be the best time for planting. I currently live in Sydney but the trees will be grown in Cooma NSW (located 1 hour from Canberra) Weather does get abit cold (-2 degrees Celsius in winter)
    Is there any specific soil that I require?

    Thank you
    Justin

  9. Mary says:

    Hi there, I have 2 macadamia trees in the back yard. One is 6 years old and the other one is approximately 15 years old. They have never flowered. What can I do to help stimulate them to flower? The leaves look a bit dull and some are brown/burnt – but we have endured a very hot dry summer. Any suggestions would be most welcome. Thank you

  10. naomi says:

    i have really enjoyed the topic…but it seems one has to plant it early enough to allow best commercial yields for many years…

  11. matthew says:

    hi i have a question for you can you grow macadamias in a hydroponics system

    thanks matt

  12. Edwin says:

    I have a healthy Macadamia tree 17years old in Doncaster Victoria.I bought the grafted plant in Queensland 16 tears ago and is now about 5 metres high. It started to fruit 4 years ago, 2009.
    My problem is that the nuts are not quite big enough.
    Any suggestions?

  13. lyn millist says:

    Thankyou for this wonderful article , I have had a small tree purchased from a nursery close by.
    I live in Sydney and the tree is now 13 years old , it is a little leggy (which I will now trim centre main stem to make branching out , having seen your article) however it has never flowered , what am I doing wrong?.
    The position faces north, west, south and is completely protected from the east, it gets sun all day and is watered well in summer when weather is dry, it has agapanthas only growing around its base but they are probably 3feet from its base. Are they the wrong plant to be growing near it ?
    Interested to get a crop
    from Lyn

  14. admin says:

    I don’t think so, they would be too big.

  15. admin says:

    This could be due to the variety you chose. Each tree variety has different characteristics with fruit size getting bigger and better with successive hybrids bred.

  16. admin says:

    Do you know the variety? Some varieties don’t produce so well being so far south as Sydney.

  17. Donna bailey says:

    I have a great big macadamia tree and I’m in Doncaster east. It produces a huge amount of nuts but I can never be bothered collecting them because they take so long to crack. Is there any commercial place that will take my nuts and crack them

  18. joseph maina ngunju says:

    Hi,
    Am joseph , living and working in rift valley , Kenya . I’ve started a 20 acre macadamia farm in Solai , 1951 meters above sea level with deep volcanic soils. My aim is to do 1500 trees at the end of 2014. I would love to get in touch serious macadamia farmers in Australia for regular consultation.

    Thanks.

  19. admin says:

    Hi Joseph, you could try keeping in touch via these websites for macadamia growers in Australia: http://www.macadamiagrowers.com/ and http://macadamias.org/

  20. Dee Whitsend says:

    I have a macadamina tree in my yard and I have a garden bed under it. The husks and leaves fal into the garden. I am wondering what are the best things to be able to grow as the husks and particularly the leaves seem to detere things to grow in this bed. Thank you Dee

  21. John Cain says:

    Great article – one question. How do you crack them open to revceal the edible kernel

  22. admin says:

    Use a nut cracker or a hammer … very carefully!

  23. Allan says:

    I live in South Africa and have a 6 year old Macadamia nut tree in my garden.
    The tree is about 3 metres tall and looks very healthy. There were many flowers
    this year and many small nuts formed but fell off when they were about the size of a pea.
    There a still a few left, is there anything I can do to stop them falling off as well .
    Is the tree too young to bear nuts that reach maturity? The tree gets well watered
    once a week.

  24. admin says:

    Like most fruit trees, the Macadamia will pollinate many more flowers than it can handle to maturity. The tree does a bit of a stocktake of it’s energy supply and then decides how many fruits (or nuts) to leave on to maturity, shedding the rest. You find this also very common with citrus. It’s possibly just coming into fruit bearing age so the tree won’t take too many in the first year. Just keep some regular watering up to it and a good supply of potash (or other potassium based fertiliser) to encourage fruit to keep developing.

  25. Linda says:

    I planted a macadamia tree years ago under the canopy of large gum trees (to protect it from frost) in our backyard in the lower Blue Mountains. It seemed to grow well despite neglect, although it does get the run off from our driveway. I have never noticed flowers, and perhaps only a handful of nuts until this year.

    I suspect we were feeding the local possums all these years, as since we have had the presence of a dog in the yard, the tree is now covered in nuts. We have just introduced a Labrador into the mix, who chews wood, bark or anything else he can get. He often regurgitates handfuls of bark and the other day a whole macadamia nut! I understand macadamia’s are not good for dogs.

    I now have the dilemma: how to protect the Labrador guide dog and the crop of macadamias. If I let them drop before harvesting them, he will surely get them. Any suggestions?

  26. The Veggie Lady says:

    Now that’s a tricky one.
    Anyone with any suggestions?

  27. Wendy Austin says:

    WE had a lovely macadamia tree. We also have a large bull arab dog who took a liking to cracking and eating the nuts.It did not seem to affect her, she’s trim and very fit, but I cant say I studied her.. not really a lap dog. Then she swallowed one whole.Probably skidded off her back teeth. It caused a gut obstruction and cost 2000 dollars ouch!The vet says he sees a lot of this and the dog wont learn as they are tasty. One dog has had 3 operations…We decided to take down the tree sadly . I have since heard or people who net the tree while it is producing nut and funnel the net to the ground. we would have had to fence the tree as well as a net woud not prevent the jaws of Suzy from obtaining her prize.Possums and rats also scatter the nuts.
    I also saw a guy on youtube harvesting the nuts with a citrus picker before they fell. He seemed to think they were ok. Good luck keeping a labarador away from a potential food source.

  28. The Veggie Lady says:

    Oh Wendy, that’s very sad news.
    Sometimes pets and edible plants just don’t go together in small spaces.

  29. Linda says:

    Thanks Wendy for your feedback. O dear, my greatest fear: thousands in vet bills for a $30,000 dog! And it’s true, Labrador’s are so food oriented.
    As the tree is quite large it might be difficult to net it. Hmm, must give this more thought …

  30. Glenn says:

    Your article on pests doesn’t mention cockatoos.

    Our 25m integrifolia tree has produced 20kg of fruit in a year, but a gang of ten cockatoos can easily eat the lot and have done for the last 3 years.

    Is there an organic method of getting rid of cockatoos that doesn’t require fireworks or a firearm???

  31. The Veggie Lady says:

    Aaahh the dreaded Cocky!!
    I’ve written about these gangs of hoodlams in another blog post, see: http://theveggielady.com/avian-trouble-makers/
    I hear you Glenn but the only way to keep them off your fruit and nut trees is to net the tree.

  32. Mugwaneza Lambert says:

    This is a golden tree.I planted only 40 trees in our country Rwanda /Africa. And per season I gain 1 tone .I thank our government for promoting this good tree

  33. Shannon says:

    Hi, We have a young macadamia tree and it has blown over a little in the last cyclone, we feel we need to cut the top off, as it is heavy and pulling it down. Is it the wrong time of year to prune, and can they tolerate a fairly hard prune?

  34. I have a Macadamia tree about 6 years old in my garden. This season it is producing quite a good crop of sizable nuts that have yet to fall. I was hoping to find details about pruning the tree in your very informative article but may have missed it. Please let me have do’s and don’ts.

    Regards

  35. Halima Sadia Sayed says:

    What do you make with Macadamia nuts?
    I once made blondies and they were excellent. Thank you

  36. The Veggie Lady says:

    Blondies are great.
    I never get to make anything with them because I like them just simply roasted and salted. So they never last long enough for me to bake anything.

  37. Augustinus. Steens says:

    Dear Madam We have a macadamia tree maybe its 15 to 20 years old, I planted it it has long pink blossems,the nuts dont fall even some of last year are still hanging in tree.
    I have two questions ” Its beginning May and one branch high up flowerd out of season ,my second question is” how do you keep the nuts as I like them the best raw, do you keep them in the shell

    I live in the North island Whakatane New Zealand

    My regards

    199 King Street Ph. 07-3085793 or cell 027-406-2567

  38. Mel says:

    My mothers home (where I grew up) in Sydney has a beautiful macadamia over 100 years old. Amazingly, it is still flowering each year and producing a staggering amount of nuts. I have the fondest memories of sitting under the tree and placing the husks into a special hole I created in the concrete and splitting the shells with my special half brick. I would sit for hours and do this and as a ‘payment’ I was allowed to eat each nut that didn’t come out of the shell in one perfect piece ;)
    A few years ago we had to have one of the major branches removed as it had died due to borers but apart from that, the tree is still thriving! My mother fertilises it every 3-6 months with slow release fertiliser and chook poop and she doesn’t clear away the dropped leaves/debris under the canopy and this helps to mulch the ground.
    The only real issue is the sulfur crested cockatoos. Mums place is near a national park and the cockies had never paid much attention to the tree until about 25 years ago when we put on a wooden deck extension – suddenly the place was swarming with them. After they ate (yes, they ate) almost all of the wood in the verandah, they moved to the tree. The only way we could stop them was to get my brother and I super soaker water pistols and spray them with jets of water (this was also how we stopped the Indian Myna birds from taking over the local Myna birds nesting spots). In a way that could be considered organic gardening :)

    I would like to plant a macadamia tree at my home in the upper Blue Mountains – it becomes very cold and frosty here in the winter; do you think it would work?

  39. The Veggie Lady says:

    Mel – Fond memories of old trees, but those Cockies can be a real nuisance!
    Not sure how the tree would go in your area, it would depend on the variety. Perhaps ask at your local nursery.
    I’ve seen them grown and produce nuts in Oakdale near Camden but it’s probably not quite cold as upper Blue Mountains. Good luck and let us know how you go.

  40. Would you please get back to me, and give me some idea just how long it takes to get nuts from the trees that sprout around our Queensland Nut Tree?

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