MABTON, Wash. (AP) - Outside, the sun barely broke through the high clouds and did little to warm the frigid air. Corn and tomato plants were dead for the winter.
But inside Hilario Alvarez's greenhouses, peppers grow just fine in the warmth and humidity. He could grow vegetables all winter long if he found the year-round market to justify the heating costs.
"They grow easy," Alvarez, 62, told a group of 30 visiting farmers and students touring his seven high tunnels, rudimentary greenhouses made from plastic stretched over curved frames.
The tour of high tunnels, named for their tubelike structure, kicked off the annual conference of the Tilth Producers of Washington, a nonprofit that encourages sustainable farming. The meetings continue today and Sunday at the Yakima Convention Center.
About 400 people are attending the conference, but the high tunnel tour attracted 60, twice what organizers had expected.
"The tour is so popular, so we're doubling it," said Michele Catalano, executive director of the Tilth Producers.
She took two groups of 30 through each of the three Lower Valley farms participating Friday, including Heavenly Hills Harvest in Sunnyside and Bella Terra Gardens at Rose Hill in Zillah.
Driven in part by a federal cost-sharing initiative, high tunnels are becoming more popular.
Since 2010, the U.S. Department of Agriculture's Yakima service center has funded 18 high tunnels through the Natural Resource Conservation Service in Yakima, Klickitat and Benton counties, with a total cost of $58,000.
Trying to help local growers extend their seasons, the Conservation District this year paid $2.55 per square foot of high tunnel construction. The structures cost between $3,000 and $6,000 and come in a variety of kits.
"It's seeming to pick up interest," said Corey Bonsen, a resource conservationist at the Yakima office. "We run out of money every year."
The office receives more applications than staff can fund, he said.
Alvarez built his high tunnels on his own, but the idea is the same.
Sometimes called "hoop houses," the structures have solid sidewalls with doors and curved metal tubing that forms a dome shape overhead. Growers then stretch transparent plastic over the top, sometimes adding black shade cloth to cool things down, and leave the dirt exposed.
Alvarez stretches drip irrigation tape along the ground.
He built his first high tunnel in 2002, adding more as the years went by. He plans to open another one, maybe by next year.
During the summer, Alvarez cranks up fans and opens the doors to circulate the air to prevent plants from overheating, or simply rolls up the sides for conventional outdoor growing. In the winter, he lowers the plastic and uses wood stoves and an automatic propane heater to keep the crops warm.
He estimates each house costs a total of $4,500, not including fuel expenses.
The hot houses give him a jump on the market. He plants his own seeds in March and transplants them in April, beating the outdoor harvest by two weeks, therefore commanding a higher price for his tomatoes, egg plants and cucumbers. Two of his tunnels grow iznik cucumbers, a variety that would not survive outdoors in the Yakima Valley's weather.
Alvarez is best known for his peppers, which he strings into colorful wreaths. He even has a variety he calls "blueberry," which he claims only he grows.
He staggers the planting of his peppers from March through May, extending his harvest through mid-November. The family still has a couple of weeks to sell pepper wreaths before closing down for the winter, said his son, Eddie Alvarez.
The family business sells wholesale to grocery stores, direct to restaurants and through about 18 farmers markets, including Pike Place Market in Seattle starting in mid-May "before everybody else floods the market," Eddie Alvarez said.
The Alvarezes could extend their season even more, but not all the markets stay open and customers aren't trained to shop for farm-fresh produce through the winter.
The advantages go beyond temperature control, he said. The greenhouses keep bugs, birds and diseases at bay.
Laura Lentz, a grower at Gibbs Farm in Leavenworth, said she also uses high tunnels with removable sides that can be left open in the warm months and closed when it cools down in the mountains.
"They're just good as an extra boost," said Lentz, one of the members of the tour.
Bill Razey of Naches may build his first greenhouse this year.
The fourth-generation grower has been reading and talking a lot about the structures but appreciated the chance to see them Friday.
His family mostly grows cherries but wants to extend his presence in the Pike Place Market with vegetables.
"It will give us something else to sell," he said.
Information from: Yakima Herald-Republic, http://www.yakimaherald.com
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