According to Tom Lochner from the Wisconsin Cranberry Growers Association, the cranberry vines started coming out of dormancy during the unusually warm 80-degree weather two weeks ago. Because of this, growers are watching for overnight frost now. Some are irrigating, or on very cold nights flooding the cranberries. This protects the vines from freezing because frost damage means less yield.
Lochner: “Most growers have some type of a system that will alert them when temperatures start to drop. At a preset level, the irrigation systems will automatically start and run until growers can get out there and check things out.”
The temperature when cranberries become susceptible to cold depends on the variety and the growth stage, and he says many growers in northern Wisconsin still have their beds flooded, while others in central Wisconsin have been using irrigation as needed to protect the vines.
Source: brownfieldagnews.com