Fears of drop in Arizona wine grapes after freeze

• At least four wineries along Elgin Road were hit hard by a mid-April freeze.
• Growers won't know extent of damage until the vines produce fruit over the summer.
• Winery owners estimate they have lost between 30 and 40 percent of their potential harvest.
• Cold%2C not heat%2C is the main worry in growing grapes in Arizona.

There is one group of Arizonans glad to see the arrival of the summer heat: the state's winemakers. Particularly those in the Elgin area who saw their grape crops damaged by a severe April frost.

"Heat's not the challenge. Grapes love it," said Mark Beres, co-owner of Flying Leap Winery and Distillery. "They do great things when they get hot. It's freezing they don't like."

Flying Leap was one of at least four wineries on Elgin Road that took the brunt of sub-freezing overnight weather. The cold hovered over four vineyards on Elgin Road belonging to Dos Cabezas WineWorks, Callaghan Vineyards, Flying Leap and Kief-Joshua Vineyards.

Grapevines typically go dormant in the winter cold, and frost doesn't damage the standing, woody part of the vine. When spring days arrive, the woody vines push out new green shoots. It's these shoots that sprout the year's grapes — and those new green shoots are highly susceptible to frost.

After losing green shoots to frost, the vine can push out a new set of shoots, but the loss will diminish that year's growth and cut into the amount of fruit a vine can produce.

The cost of this freeze won't be known for months. Growers estimated they lost between 40 and 60 percent of their harvest off these vineyards. And the quality of the fruit that does come in won't be known until harvest.

It's also not immediately clear what effect this will have on wine pricing. The affected wineries might have to buy grapes from other area vineyards to keep up production levels.

The April cold did not affect the state's largest wine growing region, in the Kansas Settlement area south of Willcox. Nor did it freeze in the state's other growing area, the Verde Valley in northern Arizona.

But the April 17 cold snap brought temperatures as low as 29 degrees and stayed below freezing for four hours or more, growers in the area said — and the longer the time below freezing, the greater the damage. One grower, Kief Manning, said his thermometer registered 23 degrees.

"We probably lost possibly close to half of the crop this year," said Manning, owner of Keif-Joshua Vineyards. "Everything that was budded out just got fried."

Manning and other growers tried using fans and heaters to keep the vines warm. "No matter what you do," he said, "it's hard to bring up the temperature 10 degrees."

A warm stretch the week before brought the vines to life, said Kent Callaghan of Callaghan Vineyards. It prompted earlier growth than usual, making the timing of the frost that much worse.

In a normal year, buds might not have greened up by late April. "We probably wouldn't even have been scratched," Callaghan said.

One of Callaghan's varietals, Tannat, "is rumored to recover well from spring frost," he said. "We'll see how well it recovers." Callaghan said the cold snap could provide valuable information in the long run about what varietals can weather the region's weather.

The 2012 vintage of Callaghan's Tannat was named Best In Show in TheRepublic's 2014 competition among wines made with grapes grown in the state.

Todd Bostock of Dos Cabezas WineWorks said his vineyard in Elgin suffered, with the exception of Mourvedre and Graciano, varietals that start budding later than most. "Everything else was out and got wiped out," Bostock said.

Bostock also has a vineyard in Willcox. It was not damaged because the temperature did not drop below freezing.

Robert Carlson, a partner in his family's Carlson Creek Vineyards, sent out temperature updates on Twitter through the overnight hours from his vineyard in Kansas Settlement. According to his Twitter feed, it hit 33.4 degrees just before sunrise.

Flying Leap also has a vineyard in Willcox, which Beres said has much different growing conditions than Elgin. Both are in Southern Arizona, but Elgin is at 5,000 feet, Beres said, while Kansas Settlement is at 4,300 feet.

"A lot of people don't understand how dramatically different those two growing areas are from each other," he said. "Elgin is a very difficult place to grow (grapes.) And I don't know how they do it up north."

Beres said he doesn't expect any more nights that drop below freezing, although there was an early May frost in 2011. Arizona growers' next challenge is dealing with the late summer monsoon storms that strike around harvest time.