Working in the vineyard with 8 inches of snow on the ground is not possible so we will shift to indoor tasks until the snow melts. A major indoor project is to investigate ways of modifying our granular fertilizer spreader to deliver fertilizer only under the vines as we move through the vineyard on a tractor. We don’t want to waste fertilizer and we also don’t want to apply what amounts to excess fertilizer that could cause foul runoff water. Fortunately, we have a piece of equipment that has not been used for 2–3 years and we are working to see if we can direct the fertilizer through hoses to the ground right under the vines. Stay tuned!
People occasionally come to the Winery right after a big snow event or during very cold weather and ask if the grapevines will survive the winter. The full answer is that if it gets cold enough, the vines may die. But, our vines are hybrids based on the native Vitis riparia (aka the ditch grape) and one or more European or other American native grape varieties. The objective in hybridizing is to get the good characteristics of both parents. Hybridizing with grapes began in earnest in the latter part of the 19th Century and much progress has been made with cold climate varieties, especially since the 1950s. Interestingly, most of this hybridizing work has been done in the Upper Midwest. The outcome is that our cold climate vines are usually able to survive air temperatures down to about -15 to -20°F.
Our vines start to shut down for the coming winter shortly after harvest. The leaves first turn brown and then almost black. A good wind comes along and blows them off the vines. The vines actually “look” dead at this point. What is happening is that sap which contains sugars, nitrates, and ammonia descends down into the roots of the vine. Keep in mind that the root system is usually similar to what the above-ground vine with its trunk, cordons, and canes looks like so there is plenty of space for the sap. The roots will continue to absorb water and nutrients during the winter. Then, when it warms up in the spring, the flow of sap reverses and it permits the buds on the vine to swell and eventually break open with leaves. The process continues until the vine is covered with leaves, flowers form, and fruit sets.
