Cold Hardiness of Grapes:  Fall frost injury

Early fall frost or cold temperature may injure vines before they are fully hardened. This is more of a problem with late maturing cultivars. Choosing a site with adequate air drainage is important in avoiding this type of injury. Cultural practices that minimize early fall injury by promoting early maturation should be followed. Do not allow the cluster to remain on the vine for any longer than necessary. Do not overcrop or undercrop. Avoid pruning, nitrogen fertilization, excessive irrigation, and cultivation late in the season. Defoliation due to combing, harvesting, or pests should be minimized. Allowing the ground cover to grow later in the season will promote maturation which is essential for the vine to harden properly.