Methods of Pruning California Grapes

Trellis

• Grape vines are woody, perennial climbers. In natural settings, grape vines use their tendrils to climb up trees. In cultivated situations, grape vines are trained to grow up trellises. Trellises are normally constructed of at least two horizontal wires running parallel from two vertical stakes. The vines are trained to grow up to the height of the stakes and out, horizontally, along the wires. The horizontal branches are referred to as cordons. Pruning methods are used to keep the branches in this cordon form.

Benefits

• Pruning helps give grape vines a concentrated form. By controlling the number of branches and buds, as well as the vines' length and height, growers are able to manage a vine's productivity in an efficient way. Instead of using energy to develop new growth and foliage, the vine's energy is turned back into the production of grapes and greater harvest yield. Fruit quality also improves. Grape vines in commercial settings are not pruned for aesthetic purposes. But well-pruned vines do have aesthetic value in a home landscape. Trellises and cordons lend symmetry to landscapes.

Spur Pruning

• Spur are points extending beyond the vine that develop flower buds and, eventually, grape clusters. When pruning spurs, you want to ensure that flowers and clusters have space to grow, but not so much space that productivity is diminished. For every 3 feet of cordon there should be 15 to 18 shoots. Each spur should have, at most, three buds, while spurs with small diameters - about one cm - should have one bud.

Cane Pruning

• Cane pruning involves assessing cane quality and removing canes that are lackluster and weak. Remove canes that are flat, have poor color, have developed in shade or lack full buds. Choose canes with buds spaced at 3-inch intervals. Cut back the cane, leaving 10 to 15 buds per cane. Ensure that four to six spurs with two buds are left at the ends of the canes, as this will encourage fruiting.