Horticultural aide memoire No. 49: Prune a grapevine
Glasshouse grapevines should be pruned now that the leaves are off and the plant is dormant. You can see what you’re doing and the sap won’t pour out of the cuts as it would if you left it until spring. Leave the main rod intact. Follow the tip of each side shoot back to the junction with the previous year’s growth. Using secateurs, remove the new growth back to within an inch of that junction. Then, cut the spurs back to a single bud each. This simple regime, repeated annually, is all that’s required. The rewards will be considerable.