Great Lakes Grape Growers Grapple with Freezing Nights
Editors note: This story was updated Wednesday morning and was originally posted Tuesday morning, March 27th 2012
Arnie Esterer of Markko Vineyard in Conneaut, Ohio, near Lake Erie, reported temperatures of 23 degrees in the area Monday night. Esterer, who has been tending his vineyards for 45 years, reported that his grape buds are still mainly tight so he does not expect much damage. “We won’t know if there’s damage for four or five days because the buds are so tight,” he said. “If they’re really damaged, the buds will turn black,” he said.
Esterer said he visited vineyards along Lake Erie in Pennsylvania on Tuesday and did not see any frost damage.
Always wary of frost, Esterer said he designed his trellises to protect his fruit. “We use a 54 inch high wire cordon because Kent State did a study that showed the temperature can drop as much as 5 degrees as you go from five feet off the ground to one foot above ground,” he said. “Having my buds four and half feet up makes for a micro climate I can control.”
The heavy, wet clay soils of Ohio also serve as frost protection, Esterer said. Since the local soil stays cold longer, the vines break dormancy more slowly than if the soil were rocky or softer. Esterer also suggested keeping vineyard grass and weeds mowed low during cold spells.
“I’ve never seen Spring this early,” Esterer remarked, “but nature takes care of itself.”
Farther north on the shores of Lake Michigan, Charlie Edson of Bel Lago Vineyard and Winery said the Michigan State University weather station in Traverse City indicated a low temperature of 29 degrees on Monday night. However, the Monday low at Edson’s winery was not below 31 degrees, Edson said. Sunday night in the Leelanau Peninsula was actually colder than Monday night with low temps in the middle twenties, Edson said. “Most of our varieties have not started to push yet, so I’d guess that our vines can now take temperatures down to 25 degrees,” Edson remarked. He believes that he biggest weather risk currently is the length of time until the last frost date. In Northern Michigan, frost can occur until May 20th. Edson would like to see the weather stay cool, but not cold, for the next few weeks to shorten the vulnerability period. “We had great vintages in 2010 and 2011, but 2012 has the potential to be exceptional if we can just get through the next few weeks,” he said.
Rockie Rick, a commercial grape grower in Southwest Michigan, said temperatures at dawn Tuesday morning were 36 degrees with clouds and some wind. Rick said the leaves were out on his Lemberger and Cab Franc and that vine maturity was running about 30 days ahead of normal. Great Lakes water temperatures are exceptionally warm this year which may protect against frost during April and May. For example, the Southern Lake Michigan water temperature is currently 48 degrees which is more typical of early May.