When and How Should I Prune My Grapevine?

Pruning is the single most important annual task in growing grapes successfully. Without the correct pruning approach, a grapevine either produces too much weak, overcrowded fruit or — more commonly — no fruit at all. The fundamental principle is that grapes fruit on new shoots growing from one-year-old wood, which means you must retain the right amount of last season's growth while removing everything else. Both timing and method matter significantly.

Winter pruning — the main annual prune

The main structural pruning takes place during winter dormancy, ideally between December and February when the sap is down. Avoid pruning in late November (still too early — sap can rise after a warm period) or after February (sap begins to flow and cuts bleed profusely, weakening the vine). Prune on a dry day to reduce the risk of disease entering wounds, and use sharp, clean secateurs. Disinfect between vines and after cutting out any obviously diseased wood.

Spur pruning for most outdoor varieties

In spur pruning, the permanent arms of the vine carry short two-bud spurs evenly spaced along their length. Each winter, cut the previous season's lateral back to two buds from the base — leaving a short stub or spur. The following season, both buds break and produce shoots; one typically carries fruit and one provides the replacement growth for next year's spur. This system is simple, builds a permanent structure, and suits most UK dessert varieties such as Boskoop Glory and Black Hamburg.

Cane pruning for high-yielding varieties

Some varieties fruit best from longer lengths of one-year-old wood (canes). In cane pruning (also called Guyot pruning), each winter you select one or two well-ripened canes from last season's growth, tie them horizontally to the lowest wire, and cut them back to eight to twelve buds. A renewal spur of two buds is left near the base to provide next year's replacement canes. This approach is standard practice in professional vineyards.

Summer pruning for a better crop

Winter pruning builds the framework; summer pruning improves fruit quality. In midsummer, pinch out the growing tip of each fruiting shoot two leaves beyond the last bunch. Remove the tendrils and pinch back any sub-laterals to one leaf. This redirects the vine's energy from vegetative growth into fruit ripening and significantly improves sugar accumulation in the berries. Also remove leaves around the bunch zone to improve light penetration and air movement.

Avoiding the most common pruning mistake

The most common error is cutting back all growth to the main framework, leaving only old wood. This removes all the one-year-old wood that would have carried fruit, resulting in a season with either no crop or only vegetative growth. Always identify last season's lighter-coloured, mature lateral growth before you start, and leave the planned number of spurs or canes of this material in place.