Walnuts NZ

June 2023

A walnut grower co-operative develops value-added products.

Making a living - growing walnuts - has become a happy reality for an increasing number of walnut orchardists, including some of the members of the Canterbury-based Trickett’s Grove, the brand of the Walnuts NZ co-operative. With its own processing and packaging plant near Christchurch, the co-operative markets and sells fresh New Zealand walnuts nationwide and is developing a range of new value-added walnut products like oil, paste and flour. Backing them and other Kiwi walnut growers is the New Zealand Walnut Industry Group.  


Walnuts are high in antioxidants, a good source of omega three fatty acids (and ‘tasty as’) and New Zealand walnuts can now be found in an increasing number of supermarkets and specialty food stores around the country, thanks to the decades-long dedication of growers, some of them having nurtured their trees since the 1970s. 


Key among them are 55 active walnut-growing members of the Trickett’s Grove Walnuts co-operative, many of whom are in Canterbury with some members also growing walnuts in Otago and Nelson. Their orchards range in size from 50 trees to more than 4000, with the largest grower producing 60 Tonnes of nuts in last year’s season to the smallest with a 100 kg crop. 


The cooperative has its own processing facility located at West Melton on the southern side of the Waimakariri River near Christchurch, where it cracks, sorts, packages, brands, markets and sells walnuts. Trickett’s Grove chairman Andrew Horsburgh says during the early years of development growers always asked the question ‘who will process and promote the walnuts coming on stream?’.


Rolling up their sleeves to take this vital step were three couples, who set up processing facilities in their regions – in Otago, Marlborough, and West Melton. Trickett’s Grove Walnuts co-operative purchased the latter in 2014/2015 and has steadily expanded operations since. Heather says new growers wishing to join the co-operative are welcome.


As well as fresh walnut kernels, Trickett’s Grove is now developing value-added products such as walnut oil, paste and flour, a gluten-free nutrient-rich alternative.


Andrew says fresh is best when it comes to walnuts. “The walnut shell is nature’s airtight container, protecting the kernels from air and light. Unlike imported walnuts that are cracked months before they reach us here in New Zealand, locally grown nuts are cracked and packaged and delivered to market in a short space of time, ensuring their nutrients remain intact and that they are delicious to eat.”


Andrew explains once the walnuts are cracked, they go through an aspirator to remove the bulk of the shell, then they come through a specialist piece of equipment like this colour eye sorter, a recent investment, which is enabling us to remove anything that we don't want in the in the customer's final packet. “It's enabled us to not only process all the walnuts a lot more efficiently, but it does it in a pretty flash way, using technology to ensure consistent and quality outcomes. It’s incredibly smart technology that we can programme several ways. It'll pick up size, colour, or walnut shell versus kernel.” 


Andrew estimates they are currently using about 10% of the sorter’s capacity, “So it’s an investment for the future that that the growers have made that will see us through for many years.” They have also recently invested in a new oil press and auto bottling plant, enabling them to meet what is ‘huge demand’.


New Zealand’s walnut harvest begins in March and runs through until late April. Andrew anticipates that in 2023, Trickett’s Grove will process well more than the 200 tonnes of nuts that went through the factory following the 2022 harvest. 


Having helped to establish the Trickett’s Grove operation seven years ago, Dr Heather North says the future is bright for walnut growers. With business partner Clive Marsh she established Lightfoot Walnuts near Lincoln over 20 years ago, and she is a co-founder of the New Zealand Walnut Industry Group, where she leads ongoing research. 


It used to be said that if you want to provide for your children, plant fruit trees; and if you want to provide for your grandchildren, plant nuts. Dr North attests that while setting up a commercial walnut orchard is a longer-term investment, waiting until the next generation for the trees to bear nuts is no longer the case thanks to the development of new varieties that produce commercially viable crops sooner – reaching full production at around 16 years – as well as in greater abundance.


The walnut industry group started searching for new varieties more than 15 years ago, bringing many cultivars into the country from overseas breeding programmes. Once is the Lara variety, which originated in France, and is proving to be a vigorous grower that produces nuts earlier and is higher yielding than the traditional New Zealand Rex and Meyric varieties.


Dr North says the industry group’s focus is on supporting commercial walnut growing through discussion and learning as well as field days where experienced growers welcome people interested in establishing orchards as a business.   


There is interest from a range of landowners, from lifestylers who want to grow walnuts on their block, to farmers with larger areas of land who are considering diversification or creating an added income stream.


Along with questions about which varieties to grow under what ideal growing conditions – a dry climate with a high summer temperature and winter chilling down to -10˚C (although late spring frosts can be a problem for some cultivars) is ideal – another hot topic is the expected revenue, and costs associated with planting and set up followed by harvesting.  


Dr North says based on her own experience and industry group members with mature orchards, there is a gross income of nearly $6,600/ha with an operating surplus of $2,800/ha after fixed costs and working expenses have been accounted for. She describes revenue per hectare as sitting somewhere between that generated by a vineyard operation and a sheep and beef finishing farm.


Included in the set-up expenses for a commercial orchard (estimated to be about $15,000/ha) is the purchase of harvesting equipment and facilities to dry the nuts, says Dr North. "But you don’t need everything all at once. Like many growers, at our Lightfoot orchard we have bought these items over 20 years as our crop has scaled up. You might do things manually at first or get the drying or other jobs done by someone else and then buy the gear when your trees are more mature and producing larger crops."


Dr North says there are the non-financial values that are also making walnuts an attractive proposition for many. “As a walnut grower you get to live amongst beautiful trees while producing healthy food that’s tasty too – and then there’s the excitement that comes with being part of a relatively new and innovative industry.”


She adds walnut trees require little fertiliser or spraying, including for the likes of blight, and new research shows orchards emit a lower level of greenhouse gas compared with many crops. "In fact, we believe walnut orchards might well prove to be carbon neutral, or even positive. It’s early days yet, but it looks like emissions in production are offset by the carbon sequestration in our trees."


Added to this, walnuts are machine harvested, so not as much labour is required as many other horticultural crops. 


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