High tunnels pay off in regions with a short growing season

Sunday, March 8, 2015

Tunnels warm the soil up faster in the spring and retain that warmth even when the outside temperature drops. Result: four or five more weeks of growth and better quality fruit and vegetables in the end

by MIKE BEAUDIN

High tunnels have been part of Ontario's farm landscape for about 15 years, but they're becoming a more important tool as farmers search for ways to meet the increasing consumer demand for locally-grown fruits and vegetables.

The tunnels are also a way to protect high-end crops from the volatile weather many believe is a result of climate change.

Kyle Oakley, whose family operates a market garden and store as a diversification of their 350-acre apple orchard and cash crop farm, believes the tunnels give him them the competitive advantage they needs to serve a growing market of urban consumers in the Georgian Bay region.

The Oakleys run Goldsmiths Orchard Market, a 2,000-square-foot retail market complete with bakery in Thornbury, about an hour north of Toronto. Their challenge is finding a way to grow high-end fruits and vegetables in a region with a short growing season. They also need a consistent production flow that isn't continually left to the mercy of Mother Nature.

In 2012, the Oakleys invested about $100,000 in nine tunnels on 1.75 acres to produce raspberries, tomatoes and cut flowers. He says the tunnels have extended their growing season for both raspberries and tomatoes by four to five weeks with significantly higher yields while also dramatically improving quality. And he believes the tunnels are the way of the future for farmers looking for ways to shield themselves as much as possible from the devastating and unpredictable swings in weather.

"Tunnels lessen nature's impact on productivity and that is going to be the way to go," says Oakley. "Mother Nature provides but also takes away quickly, too."

Becky Hughes, a researcher with the University of Guelph, understands how high tunnels can be used in harsher climates. A member of an Ontario team that has been studying high tunnels to grow raspberries and strawberries since 2013, Hughes operates a trial high tunnel in New Liskeard, 500 kilometres north of Toronto. She's learned firsthand that tunnels can produce in the north.

Hughes says there's no secret as to why high tunnels are effective. The tunnels modify the climate so the soil warms up faster in the spring and retains that warmth even when the outside temperature drops.

Hughes's research has shown that raspberry quality is 10 times better and the yield is four times greater than conventional horticulture. She says consumers in the north are shocked when they learn that the strawberries they're buying in the fall are grown locally and not imported.

For Hughes, though, the future of tunnels isn't just about improving the growing conditions and profitability of farmers. She believes the tunnels may also be a way for isolated native communities to grow their own produce and become more self-sufficient.

Adam Montri, a hoophouse outreach specialist at the University of Michigan, says high tunnels and hoophouses, a smaller version used primarily in the United States, are being used extensively as the buy-local movement grows.

"We're seeing traditional farmers, new farmers, young farmers and old farmers adopt this approach. People want access to high-value food year round, especially with the trend toward local."

However, high tunnels aren't the answer for all farmers. They require careful management and planning to control costs and to justify the startup capital. Oakley says it took them five years to figure out how to maximize profit, especially given the high labour costs.

They need 750 man-hours to roll the skins back over the frame in the spring and another 500 man-hours to roll them down in the fall. There's an ongoing labour expense to vent the tunnels to regulate temperatures; spider mites and mildew thrive if the temperature is left unchecked.

There's also a hefty labour bill to pick the high-quality raspberries and tomatoes. The Oakleys start out with about a dozen workers in the spring and expand that to 20 by August. BF