By Mary Bernard, Master Gardener
Pruning of grapevines in the home garden should be performed
during the dormant season – from January through March 1. Many home grape growers prune their vines too
lightly. Proper pruning modifies the size
and form of the vine, making it a better producer of high quality, good-size
fruit. Pruning also aids in balancing
vegetative growth and fruit production.
Mature vines should be pruned yearly to remove all growth except new one-year old fruiting canes and/or renewal spurs. Clusters are produced on shoots that grow from buds on one-year old canes.
Grapes should be spur pruned or cane pruned. Most grape varieties are spur-pruned. The dormant shoots from the previous summer’s growth are selected and spaced along the vines’ cordon at 6 to 8 inch intervals. Select shoots that grew upward in a well-lighted environment for fruitful spurs. Shoots that grew in the shade the previous summer often do not contain fruitful buds. Prune back to several buds and remove all extra shoots. Short spurs (2 buds) should be left on fruitful varieties such as Cardinal, Exotic, Ribier, and Muscat of Alexandria. Long spurs (3 buds) are sometimes used for moderately fruitful varieties such as
To cane prune, select two to four new fruiting canes per vine. Again, canes which developed on the top of the vine and which were exposed to light during the growing season will have buds that are more fruitful. You should retain the well-matured round canes with a diameter of 3/8 to 5/8 inch. Leave about 20 to 30 buds per plant for wine grapes and 50 to 80 buds per plant for table grapes, such as Thompson Seedless. Remove all other one-year old wood.