With bud break on Chardonnay happening last week, the beginning of the 2016 growing season is here. At this point, it’s hard to say what it will bring because so much can happen between now and the point at which we begin to pick mature fruit in the fall. But I’m optimistic, particularly in two areas than can be a concern. First, we’ve had enough rainfall this winter to fill the soil moisture profile as deep as we need for the vines’ roots. That means they should begin spring growth with more than adequate moisture available. And second, while it is too soon to get too excited, I’m seeing two bunches per shoot on those shoots big enough to show bunches. This could translate into a decent crop if everything progresses in a straight line.
But there are a couple of hurdles we must get past during the next two months, and they have to do with damage to new vine growth. Between the beginning of March and the end of April, the vine growth is in a very vulnerable stage. All of the growing tissue – the canes, the leaves, and developing fruit – are tender, soft and are susceptible. These are the parts that carry the new crop and are extremely important, but a twist in the weather can cause wide-spread damage.
It’s not so much the rain that we are worried about, but the unpredictable weather that can come in on the tail of a storm. One of these is hail. After a spring rain in April last year, hail storms developed in the ensuing atmospheric turbulence, sweeping over a large swath in our area. Icy granules pounded the tender vine growth for twenty minutes, leaving behind broken shoots, shattered bunches and vines stripped of leaves. Fortunately, hail storms are usually small and isolated, but if your vineyards happens to be struck, you have good reason to be concerned.
Another big danger this time of year is frost. After a storm moves out, the low pressure in the atmosphere can cause very cold air to be sucked into the area. Like hail, damage from frost can be spotty, but low-lying regions, particularly the valleys in hilly country or flood plains near a river, are very vulnerable. All it takes is for the temperature to drop below freezing for just a few minutes and damage can be done. Leaves are the first to suffer, but fruit and canes can also be burned back to the trunk. I’ve already been hit by frost this year in a small portion of one of our vineyards, shown in this recent photo.
Unlike hail, though, there are things you can do to prevent frost damage. Keeping the vineyard floor clean allows the sun to warm it during the day. Stored residual heat, released at night, can make a difference in the early morning temperatures in the vineyard. Another strategy is to run water in the vineyard at night. Sprinklers, driplines or surface irrigation all put 55 degree water into the ambience, potentially influencing the air temperature enough to avoid a disaster.
Many vineyards have sprinkler systems to help protect the vine growth from frost. By running the sprinklers when the temperature drops, the water on the shoots and leaves freezes. The ice, at 32 degrees F serves to insulate the plant tissue and protect it from damage when the air temperatures drop below freezing.
So keep your fingers crossed for your local wine grape growers. This is a touchy time of year.
- Posted by Tom Hoffman
- On March 19, 2016
- 0 Comments