Grapevines grown for fruit production need pruning each year for the vines to spend less energy producing foliage and more energy-producing fruit. Trimming the grapevines during the dormant season keeps disease and shock to a minimum so the plant is not damaged during the pruning process. Control the damage to the vines by making sharp cuts with the pruning shears or knife. Remove the fruit and foliage before starting any pruning of the grapevines.
Locate the main stem of the grapevine and remove any debris and dead or diseased vines. Exposing the main trunk provides a better visual of what needs trimmed and what does not need removed. Mark the year's growth with colored tape. Mark off the previous season's growth with another color.
Replace worn or broken ties and secure new cordons with wire stays. The cordons are new growth needing trained for next seasons fruit production. With everything securely fastened and marked, it is easier to prune the grapevines.
Remove old third-year vines by cutting with the pruning shears. The second-year growth will produce the grapes for harvesting next fall.
Cut the second-year cordons back, leaving four or five spurs per cordon. The spurs hang down from the trellis and have the buds which produce the grapes. Each spur should have 30 to 40 buds left after pruning.
Remove the trimmings from the area to reveal the vines left on the trellis. Continue pruning back any unwanted growth or cordons until the desired number of cordons and buds remain on the grapevines.