What happens to a California Grapevine in the Winter?

Posted on November 18th, 2014

It’s something most of us don’t think much about but the California grape growers have work even when there is no longer fruit on the vine.  They must prepare for the new spring growing season.  Grapevines must be cared for to continue producing a quality crop year after year.  In the U.S. – the oldest grapevine can be found in the Carolinas.  It is 400+ years old!  That vine has had many hands caring for it over the centuries.

California Dormancy and Pruning (December  through February)

This winter season is referred to as, dormancy.  Dormancy is triggered by shorter days. The vines are then pruned and allowed to rest.  Training the vines to grow along wires helps during the growing and harvesting cycles to produce superior fruits.  Exposing the buds to the most of amount of sunlight possible helps to produce juicy, abundant grape bunches.

It’s important to decide how much and which parts of the previous season’s growth to remove in order to control growth of the shoots and leaves and produce a quality grape yield.

The spur method of pruning vs the cane method

Different varieties of grapes respond to different care in pruning and training.  Most often the grapes are pruned using the spur or the cane method. Old grown is cut off and the remaining new fruiting wood is determined by the differing methods.

Spur pruning is more common and easier than cane pruning.  Spur pruning generally occurs on vines that have been cordon trained.  A cordon trained vine looks like the letter T when bare.  The goals are evenly spaced spurs with one year old wood and to reduce fruit bunch crowding and ultimately disease among the new growth in the spring.

Some varieties such as Thompson Seedless respond better to cane pruning.   Canes that produced the previous year’s crop are cut off and replaced by new ones – effectively 90% of the growth will be cut back leaving one year canes that will then be tied down to trellis wire to produce the new grapes.

Keeping out the critters

With well pruned and trained vines, keeping the critters at bay is another concern. Barn owls are often provided housing to introduce rodent control to the vineyard.  It is quite common to see owl boxes in vineyards to attract the owls to control gophers and other rodents that chew and inflict damage the vines and fruit.

Consistent moisture and pest free vines will ready the vineyard for spring growth and a late summer harvest if all goes as planned.