How to Trim a Grape Arbor

Separate the strongest-looking grapevine cane (otherwise known as the trunk) during the dormant winter of the first growing year. Trim back completely all growth other than this main trunk. Loosely tie the trunk to an arbor post (usually there are four grapevines, one at each arbor post).

Allow the main trunk and all side vines and canes to thrive with no trimming until the spring of the second year. During this time, cut back only dead or broken canes. Continue to secure the vines and trunk to the arbor so the vines grow upward. In spring, determine the strongest cane on either side of the main trunk. Trim back all side growth except for these two canes.

Trim back only the foliage that becomes very clumped or crowded on the sides, the dead or broken canes, and 1/3 of the healthy side shoots from the second year spring up to the third year spring season. Continue to tie the growing canes to the arbor post to keep a basic shape. Trimming back the healthy side shoots encourages the main trunk of the grapevine to push upward.

Pinch back the top of the main trunk once it has grown to the height you desire, which usually takes awhile, since it is up over the top of the arbor.

Trim back the main side canes during the third winter so there are 12 buds on each branch, otherwise known as renewal buds.

Trim with this method for the rest of the grapevine's life. Every year, allow one additional renewal bud to grow on the tip of the two main canes, to extend the 12 renewal buds. This provides about two new shoots per year, which will increase grape production every year.