Winter is the appropriate season for pruning grapevines, although growers can prune any time after the leaves drop in the fall and before new buds form in the spring. Growers in severely cold climates can protect their vines from frost damage by pruning after the coldest months.
Vine owners also can use a double-pruning process if they fear grapevine frost damage. Double-pruning involves cutting the canes to a longer length in the winter, then cutting closer to the buds once they break out in the spring. Pruning late in the season often causes the vines to bleed sap, a condition that doesn’t damage the vines.