David Coulson's other passion is bamboo.
In 1995, he attended the world bamboo symposium at the University of Hawaii, in Hilo, and met experts and growers from around the world.
The self-professed "gardening nut" became obsessed with the idea of a sustainable bamboo forest of his own and started growing it seven years ago, harvesting his first crop after four years.
He cultivates 35 types, ranging from black and golden, to palmata, double red, Castillon and a type whose tips look like a samurai's headdress.
"I have timber species, too. They don't get to the girth they do in Asia, so when we build something with it, we use two rows of it instead of one.
"It's amazing stuff. Some bamboo grows up to four feet a day and it's wonderful for all kinds of things. I use it in interior design for curtain rods, screens and outside for gates and fencing. I'm also splitting it for exterior, horizontal siding, to give a shoji effect."
It can only be bent and shaped when it's green, so once the enormous lengths of up to 30 feet are chopped, they must be processed quickly.