We finished pruning our vines last week, just before the end of winter. All told, we pruned about 2300 vines. Mike did a few, and our vineyard manager brought in a crew of 3-4 people to do the rest over a couple of days. 

Winter pruning is the first step in quality and ripeness control for the grapes that we’ll harvest in the fall. After growing through the spring and summer, our vines typically stretch six feet in each direction along their trellis, and multiple smaller stems (aka ‘shoots’) have branched off as well. In other words, it’s a big tangle of wood. 

So our job in winter is to prune all of this annual growth back to nearly zero. We do this because it helps the vines get started again when they come out of hibernation in early spring. Pruned vines no longer expend energy supporting that big, old infrastructure of wood, which leads to better new growth in the long run. But we also prune to prevent too much growth. Having a massive bounty of grapes typically comes at the expense of grape quality and compromises the grapes’ ability to reach peak ripeness by harvest time. It’s a balancing act and we’ve honed our instincts for it over the last 25 years…

Pruning itself is straightforward, but there’s more to pruning than cutting a vine here and there. For starters, grape growers put thought into the date when they prune, trying to guess what the weather will be like when the vines experience “bud break” (the start of new ’shoots’ growing, and the end of winter hibernation). 

Typically, ‘bud break’ comes with the first warming of spring, but if you prune just before, the act of pruning shocks the vines and delays bud break by a couple of weeks. That can be helpful if early spring looks to be cold and moist enough for frost to settle on the vineyard during the nights. Frost can damage or kill young buds very quickly, and so every year, we decide to either let bud break come naturally, or use late winter pruning to push that back and give the vines a little protection against frost (we still have to guard against frost even after a late bud break, which we’ll talk about in another post). 

Why not always do a late pruning to gain a couple weeks of frost protection in early spring? Because delaying bud break by a couple of weeks also delays the grapes reaching peak ripeness at harvest time (you simply move the growing window back by a couple of weeks), and if you have a cool early fall several months later, then the grapes may never reach peak ripeness.

So pick your poison! In our case, this winter has been so moist and cold that we opted to delay bud break…and now we’ve got our fingers crossed for some warmth leading into harvest!