Pruning Backyard Grapevines in the First Three Years (Ohio State Extension)
Grape gardeners often become confused as to what should be pruned off and when. Proper pruning will help maintain a grapevine’s potential of producing a good quality fruit crop, develop good vine structure, increase sunlight exposure into the canopy, promote the development of next year’s fruiting wood, and potentially reduce disease and insect pressure.
The key to good pruning is learning how to select good quality fruiting wood to leave for cropping.
As green shoots mature in the late summer and fall, they will begin to harden-off by developing a periderm (bark layer) that is reddish-brown in color. Healthy shoots will harden-off the full length of the shoot. Any green growth (generally at the tip) remaining at frost will be killed.
Proper pruning can help to reduce the amount of unproductive wood and balance the level of fruit crop with the overall vegetative growth each year. Once pruning is completed, the remaining fruiting wood should be spread out over the entire allotted space for the vine on the trellis.
How do I Prune my Grapevines after the First Year of Growth?
In the first growing season, remove all fruit and unwanted lateral shoots from the young vines throughout the growing season. Grapevines tend to grow rapidly from the apical end (main growing point) when lateral shoots and fruit are removed. Vines should be staked and tied (using twine or string) to allow the new shoot to form a straight trunk (Figure 1). The leaves should remain on the developing trunk to produce necessary carbohydrates to feed the plant; all lateral shoots, however, should be removed. Only lateral shoots at the top wire will be left. New growth may reach the top wire (around 5 to 5½ feet) during the first year. If this occurs, pinch off the end of the shoot(s) at the top wire and then the lateral shoots will grow horizontally in both directions along the top wire. These will be used to form the new cordons. Pruning of one-year-old hardwood (dormant canes) will be minimal, but some pruning may be necessary to help shape the vine before second-year growth begins.