Q. I have four grapevine bushes. We had a freeze these past two years. Two of them are doing fine, however, two others have not produced new leaves since last year. Does that mean they are dead? How would I check if they are dead?
|This grape was from a previous reader in Canada but a dead grape vine is a dead grapevine, right?|
A. Some grapevines are more tender to winter freezing temperatures than others. Some of the European wine grapes, or those with wine grapes in their heritage, may possess less tolerance to freezing temperatures. We refer to these grapes as “vinifera” type grapes. Thompson Seedless, for instance, is in this category and many California table grapes.
Most of these grapes will not tolerate temperatures much below 20° F. Expect them to freeze to the ground while other, hardier grapes may sail through the winter unharmed.
If you don't live in wine grape producing areas, I prefer to grow grapes on their own roots rather than grafted onto a rootstock. If they freeze to the ground many of them will regrow from basal suckers. If they are grafted on a rootstock, then you might as well throw it out.
Cut the top of your grape back, close to the ground. Let it sucker from the base. Select the strongest sucker and re-tie it to a grape stake with nursery tape. Remove the other suckers.If you push its growth hard with water and nitrogen fertilizer, you can reestablish it back on the trellis in one growing season. With some grapes I have been able to regrow it on the trellis and have it set fruit during first year of establishment.