How and When to Prune a Grapevine. Grapes should be pruned during their dormancy, usually in late winter. When it comes to pruning grapes, the most common mistake people make is not pruning hard enough. Light pruning doesn't promote adequate fruiting whereas heavy pruning provides the greatest quality of grapes.

When should grapevines be cut back?

When the vine reaches its third year, it's time to prune it as a mature or proper grapevine. Peter said this involved looking for two canes that would carry a reasonable crop the next season and two replacement spurs. "The spurs set up next year's canes," he said.

Do grapevines need to be cut back?

Grapevines are normally considered to be mature and fully productive in year three. Dormant pruning should be completed starting in late February through March. One-year-old wood (the previous summer's growth) should be pruned back to three to five nodes per spur. The spurs should be evenly spaced along the cordon.