Hamilton and wife Lynda have 700 walnut trees planted on a 5.5ha plot on Teschemakers Rd.
They are part of a group of nut growers who have purchased a Christchurch processing facility, where nuts are turned into a range of value-added products such as oil, flour, broken and whole raw nut kernels.
''It's quite exciting. We can't grow enough of them.''
When Hamilton started in 2002, New Zealand was importing 500 tonnes of nuts annually. It now imports 800 tonnes.
There are two other nut processing plants in Christchurch, including the Canterbury Nut Company, which produces hazelnuts and nut butter and Uncle Joe's in Blenheim, which makes a variety of hazelnut and walnut products including award-winning oils.
The Hamiltons' endeavour goes back to his father and grandfather's love of growing trees.
He then read an article about growing nuts by Otto Mueller in Central Otago and that ''planted the seed''.
Then he got to see the research the walnut industry was doing at Lincoln University. ''That germinated the seed.''
He saved up, bought a piece of land and planted four different varieties of walnut trees 15 years ago.
It takes walnut trees 15 to 20 years to mature and begin producing a decent quantity of nuts - between two and four tonnes per hectare. He currently gets nearly a tonne.
At present, the operation was ''a day off and weekend project'', which only requires ''some mowing and spraying''.
''Then we pick them, wash, grade and dry them before they go to the factory in Christchurch.''
