Ask North Islanders what the greatest thing going against Southland is and chances are they'll say the weather. Not so, says Waikato berryfruit grower Greg Furniss.

Winter chill is exactly what enticed him to start a blueberry operation between Otautau and Drummond that potentially will be bigger than both of his base farms south of Hamilton. "The reaction that most people have to coming to Southland is one of the climate," Mr Furniss said.

"I've been down there four or five times since last May and quite frankly I can't see why they would be complaining. It's really much the same as the Waikato – maybe a little bit colder. It's got some downsides as far as weather is concerned – we probably stand higher risks of early and late frosts. But we think that the risk is worth taking."

The decision to add a southern wing to Blueberry Country Ltd was dictated first by soil type, not location. Mr Furniss scoured the country looking for a place to diversify.

It was a commercial decision, essentially a risk-spreading exercise. "We were looking for land that was in its natural state, never been farmed, never been contaminated, if you like, by farming practices. Blueberries are a swamp plant, a wetlands species and there is very little wetland that is suitable.

"By that I mean once you start pasture farming on the raw peat soils you introduce grass species, weed species and in particular you raise the pH and all that is foreign to the environment that blueberries really like."

Finding the right location took about two years. "I basically tracked it down by word of mouth." Once he identified the soil type, he had to be sure the climate would give him optimum balance between warmth and chill to set the fruit.

So he turned to Topoclimate South. "We needed to know how many hours from fruit set through to harvest that were above 18degC and how many that were between 13 and 18degC. That's the model we needed for ripening."

The frost information was easy to find but the cumulative hours at those temperatures took a couple of months to be sourced. The raw data was there but because the Topoclimate project was relatively new, it took time to capture exactly what he wanted.

"I think they are still relatively unfamiliar with the data they've got and how to extract it in meaningful forms for people." Despite that, he was confident the basic formula was right and the information was there to help people make informed decisions based on accurate soil and climate information.

By September last year he had an unconditional agreement on the property. Already four people are employed there, three fulltime, tending a nursery with about 300,000 plants.

Blueberries are susceptible to wind damage and the mortality rate in young plants is high. It is expected between 150,000 and 200,000 bushes will be ready for planting out this winter.

It was likely to be about four years before commercial picking began – eight before the orchard started producing a positive economic return. "Once we get into full production we'll probably end up with a seasonal labour force of somewhere in the region of 50 to 100 and a permanent staff of somewhere in the region of about 10 or 15."

At just more than 200ha, the Southland property is bigger than both his North Island properties, which cover 160ha. Blueberry Country Ltd was founded about 12 years ago. Most of its fruit is sold on the domestic market with some going to Australia.

Crazy though it might seem, Blueberry Country imported 100 tonnes of blueberries from North America last year for the growing domestic market. More will be imported this year because an early frost in the Waikato reduced the crop.

Mr Furniss is confident the new-found popularity of blueberries in New Zealand goes beyond simply being a trendy ingredient for muffins and pies. "I think their health benefits have been identified recently and I think that's probably given the market a real boost. I don't think it's just the flavour and the taste."

Research in the US suggests a diet regularly including blueberries may help with brain aging. Experiments in rats have shown 70-year-old rat equivalents with the brain and muscle age of 40-year-old rats.

Blueberries are also believed to have benefits for urinary tract infections and eyesight problems. Mr Furniss is one of his product's greatest advocates. "I usually try and eat about a cup a day. I'm 52 and I feel all of about 25."

But despite the huge popularity in recent years of blueberry muffins – one of the fastest-growing areas of the markets – New Zealanders still consume blueberries in only small quantities by US standards. "New Zealanders probably consume four or five times the number of strawberries as they would blueberries. I'm biased but I think blueberries have got a lot more going for them than strawberries," Mr Furniss said.

The most recent Ministry of Agriculture and Forestry statistics show in the year to June 2000, there were only 348ha of land in New Zealand planted in blueberries. HortResearch figures show the crop volume of that area was 1130 tonnes with export sales value of $5.9 million.

New Zealand's total fresh berryfruit exports in the same period totalled $20.1 million with strawberries being dominant.