After harvest and a very busy spring, summer, and fall, the "wine growers" collapse into a much needed rest. God gave farmers seasons for a reason. It is like working six days and resting on the Sabbath. Winter is a time of relative stillness, tranquility, and slumber. We sit by the fire, tend the animals, and tend the developing wines in the winery. Cold and short days don't allow for much outside work.
During the summer, the vines are pouring their all into the fruit. After harvest, the vines can focus their energy on other important things. The time between harvest and the first frost is critical for the upcoming year's success. The leaves are still large and green during this period. They are soaking up vital energy from the sun. Photosynthesis is happening. The trunks send down many new roots (Root Rush) which are absorbing nutrients and water from the soil. Like a bear storing up fat for the winter hibernation, the vines are doing the same. That is why we don't prune grape vines in the fall. They need every leaf possible for creating these vital energy stores. It is a race against time to build up as many sugars and carbs as possible before the first frost.
After the frost, the leaves on the vines turn brown and fall off. Now something very special happens. The sugars, carbohydrates, and water that are stored in the woody parts of the vine begin to act like antifreeze in the plant. Each grape varietal is different, but many can withstand temps to 12 degrees and below without freeze damage.
So, a wise wine grower waits as long as possible to prune in the winter. We don't want to disturb those precious stores of energy and built in cold protection. The vines "weep" some of this sweet water after pruning. Pruning also tends to encourage new spring buds (bud break). We don't want bud break to occur until we are fairly certain that a hard frost is unlikely. In our vineyards at Trillium we prune around mid March, because bud break usually begins around April 1st. At bud break the plant calls on its stores of energy to produce buds and the lush and rapid spring growth. Flowers follow and then the grapes. Like a toddler, the vines wake up running and need all the energy they can get.
The vines and the vineyard workers have about another month before the outside work, busy schedules, and long days begin again. Rest well and sweet dreams!