How to renew a grapevine cordon

When to renew a cordon

• Periodic removal of cordons will be necessary to maintain productivity.
• Remove cordons when yield declines or when there dead areas on the cordon, poor spur locations, or too few spurs.
• Renewal requires pre-planning: Maintain a shoot at the head of the vine (to of trunk) or sucker along the trunk during the growing season for replacing the cordon during winter pruning.

How to renew a cordon

• Cut out the old cordon by starting from distal portions of the cordon and work toward the vine trunk. This will allow you to assess vine health (look for cankers as noted in the video).
• Be sure to select a new 1-year old cane from the trunk to replace each cordon, making sure it arises from above the trunk graft union (to ensure training from the scion cultivar rather than the rootstock).
• Position the cane on the wire, wrapping it no more than one rotation and affix.
• Unwrap the new cordon the following winter so that it does not grow around the wire over time. This will lead to girdling if left wrapped.
• Continue to maintain a renewal spur at the top of the trunk (head) for future cordon renewal.