TRAVERSE CITY -- Northern Michigan vintners hope there's enough summer sizzle left this month to ripen a grape crop stunted by an uncommonly cool growing season.
The region's grape crop is running at least two weeks behind last season's crop, said growers, who are doing what they can to ensure their vineyards receive as much sun and warmth as possible in summer's waning days.
Without that hands-on care, some varieties won't ripen as needed to produce adequate sugar content for top-quality wines.
"It's a real question as to whether it is going to ripen or not," said Warren Raftshol, of Raftshol Vineyards north of Suttons Bay in Leelanau County. "This is one of the worst years ever. We've had virtually no summer whatsoever."
Raftshol's 12-acre vineyard off M-22 normally provides enough grapes for his fall wine production, but he may have to look for fruit from southern Michigan or elsewhere this year.
"This year is so out there," he said. "I don't know if we'll have enough grapes to make wine out of."
The lagging grape crop also concerns local agricultural officials.
"The grapes I'm worried about," said Nikki Rothwell, director of the Northwest Michigan Horticultural Research Station in Leelanau County.
Rothwell checked local vineyards last week and said the region's crop is "having a hard time" ripening after a cool, damp summer.
"I don't see very many grapes approaching that period where they're coloring up -- and it's September," Rothwell said.
Weather statistics from July and August illustrate the problem. Wine grapes thrive in hot and dry weather, but this season has been noticeably cooler than recent summers.
A typical Traverse City area July features average high temperatures of about 80 degrees, according to National Weather Service 40-year averages. But this year's July average high reached just 74.2 degrees, said Scott Rozanski, a weather service meteorologist in Gaylord.
The pattern continued in August, when the 40-year average high temperature fell about four degrees below the normal 78.5-degree mark.
And no 90-degree days were recorded in July or August this summer, Rozanski said, after two 90-degree days in June. A typical northern Michigan summer has at least five days of 90-degree weather.
"It just never became warm for an extended period of time," he said.
Yield won't be a problem for this year's crop, slow fruit development aside. Michigan's projected grape harvest of 98,000 tons is up 33 percent from last year, while the national harvest is expected to dip by four percent to 7.03 million tons.
"We're going to have a good-sized crop; no doubt about it," said Mark Johnson, the winemaker at Chateau Chantal* on Old Mission Peninsula. "It's going to be good quantity year."
Wineries are taking steps to help the crop along. Johnson said his crews are working in vineyards to trim excess leaves and vines so fruit can soak up available sun. They're also cutting away some grape clusters so remaining fruit can more fully develop.
"We've been doing everything we can," he said.
The cool summer isn't as much of a problem for local grapes used for white wines such as riesling or pinot gris that don't need as much heat to fully ripen.
Johnson said he hasn't given up on the season; an extended period of warm, dry weather could coax the grape crop to where it needs to be. Growers can push harvest to mid-October and beyond, if grapes continue to ripen.
"I just hope we can get six more weeks like this," he said.
The bulk of the national grape harvest comes from California, where 6.25 million tons are projected, down four percent from last year. Other states that grow more grapes than Michigan include Washington, projected at 395,000 tons, up 13 percent from last year, and New York, where an anticipated harvest of 140,000 tons would slip 19 percent from 2008.
Local winemakers said cool weather helped in one area: Tourists and locals flocked to their wineries this summer.
"The cold weather kind of drives people into the tasting rooms," Raftshol said. "It's been pretty brisk business."
Due to an editor's error, Mark Johnson was originally associated with the wrong Old Mission Peninsula winery. He is the winemaker at Chateau Chantal.