Winter Dormancy

Here begin your 2012 wines!

Whether a vine is a clone, a hybrid, a cross or a mutation, it follows a certain annual growth pattern. Your 2012 grapes will begin with bud break in the spring, culminating in harvest in the fall (in the northern hemisphere.) From a winemaking point of view, each step in the cycle plays a vital role in the development of grapes with ideal characteristics for making wine.


If you visit Napa Valley right now, the vines appear somewhat unexciting... no leaves, no grapes. The vines, however, are not at all inactive. Following harvest, vines want the same thing we want around the holidays: carbohydrates! Using the process of photosynthesis, a grapevine creates carbohydrate reserves which it will store in roots and the trunk. The vine continues accumulation until the appropriate level of reserves have been stored for winter energy and for the upcoming growing season.

At some point, chlorophyll in the leaves begins

to breakdown and the leaves change color from green to yellow, and then fall off. The vine now enters its winter dormancy period. There will be no leaves or growth activity until bud burst the following spring.

This is a critical time for grapevines; they are exposed to potentially damaging low temperatures. Acclimation begins, where the grapevine transitions from a non-hardy to a fully hardy condition. The ability of a dormant grapevine to tolerate cold temperatures is termed as 'cold hardiness'. Grapevine cold hardiness is a highly dynamic condition, influenced by a number of growing conditions and environmental conditions, varying among grapevine varieties.

Mid-winter, the period of most severe cold and greatest cold hardiness, might not be the best time of year for your vacation pictures, but it's the first chapter in the grape's annual journey and the first step to your 2012 bottles!