"We eat them all day, and we never get sick of them - we even have them on our cereal for breakfast, in salads and for dessert," daughter Grace said.
The berries were planted six years ago and are having their second "decent" harvest this season. By the end of January about two tonnes will have been harvested, Robyn Walford said.
She and husband Matt moved to 6ha in the valley 14 years ago. He had been a logging contractor and they now enjoy a rural lifestyle, supported by the blueberries and about 400 hives of bees.
Blueberries need a lot of nurturing to get established. They like a soil pH of 4.5 to 5.5, and lots of compost and mulch. For the first years berries should be picked off well before maturity, so that the plant puts its effort into growth.
The bushes are prolific croppers. Early effort and restraint pays off when they reach full production - still two years away for the Walfords - with a harvest of 10 tonnes per hectare.
Mr Walford researched the many varieties of blueberry and chose to plant mainly Bluecrop. They built a $40,000 netting shelter over the bushes, to keep blackbirds and thrushes out.
"There would be nothing left if we didn't have netting," Mrs Walford said.
The plants are fed with a seaweed/fish fertiliser, weeds are controlled by mowing, organic sprays and bark mulch, and each bush gets 50ml of water a day.
The Walfords concentrate on quality. They considered getting organic status, but Mr Walford said that might be difficult with kiwifruit spraying right next door.
Picking begins in mid-December. Much of it is done by the Walfords' three daughters and their friends, during summer holidays from school.
"They come and stay for the weekend, pick blueberries and hang out with their friends."
Blueberries grow in bunches but the individual berries ripen at different stages. They have to be picked berry by berry. Bigger growers use machines to shake the bushes, which reduces quality.
The fruit is sold by the roadside in 225g packs for $5 each, as Ngaturi Blueberries. The Walfords also sell a lot to Moore Wilson's in Wellington, and some to Farro Fresh in Auckland, with the Good Boy label.
If there are enough picked Mrs Walford takes them to each River Traders' market in Whanganui. She sells 70 to 80 kilos a week there.
- The Ngaturi Blueberries pick your own day is on Monday, January 23, from 9am to 4pm. The berries are at 268 Mangamahu Rd, 2.7km past Wyley's Bridge.
