Grape Plants in Winter

Erosion Control

• Depending on the region, rainfall can occur enough to make erosion control for planted vines necessary. This is especially true in California vineyards, which can experience heavy rainfalls in late autumn through winter. Cover crops --- established ground cover plants to hold soil in place --- straw mulching, installation of water bars on roads and drainage system maintenance are common, sustainable efforts to winterize vineyards to prevent erosion.

Pruning

• Pruning is a crucial aspect of cultivation affecting vine balance that takes place midwinter. Extensive pruning after grapevines enter winter dormancy encourages productivity during the growing season. Cane pruning involves trimming back all existing canes, or horizontal vines, to two or three buds and identifying new fruiting canes and renewal spurs, which supply the new fruit canes for the next year's growing season. Prune canes back to one or three buds. Retaining too many internodes --- the intervals on the stem between nodes, which are the points at which lateral buds and leaves grow --- the vine will not have enough growing power to develop healthy, well-ripened grapes. Where injury from severe winter weather is likely, postpone heavy pruning until early spring.

Propagation

• The Texas Agrilife Extension explains that dormant hardwood cuttings, which easily root, propagate most grape cultivars. Collect cuttings during the winter from healthy, mature vines older than three years. Choose well-developed, current-season canes of medium size and with moderately short internodes. If you over-cut and retain too few internodes on the cane, the resulting "growing" branch will not flower and bear grapes. Retain about a thumb-length stick extending beyond the last node. The following spring should see budding on these nodes and produce grapes.

Wiring

• Wiring occurs during winter pruning, allowing you to train, or direct, the growth of the vine. The Four-Arm Kniffin is a popular pruning method that uses wire to train the vine. During winter pruning, the four best canes are wired to two horizontal wires attached to the vertical posts supporting the main trunks while the other non-essential canes are removed. Select the two strongest canes to tie to the wire in each direction, which become the "arms" of the vine. Each following winter, replace the arms with canes from the renewal spurs, retaining all new renewal spurs. Pruning removes all other canes.