Weather Watching in the Vineyard

The average date of the last frost in the lower High Plains is right around the first of April. But this is West Texas. So, anything can happen.

As far as most crops grown in this area are concerned, a frost right now doesn’t mean much. Maybe a delay in soil temperature reaching the optimum planting number, but no real damage is done crop wise, because nothing is in the ground at this point except some winter wheat.

But for a grape grower, a frost right now could mean the loss of thousands of dollars in revenue. So, is the danger of frost behind us? Well, there are a couple of schools of thought on that.

For one, the mesquites have started budding. The mesquite has been known as the last hold out for spring. Once the mesquites begin to bud, you can usually count on the frost danger being behind us.

The opposing view is presented to us courtesy of the “Pink Moon” scheduled for April 11. Tradition tells us that a full moon in April means there will be another frost in April. This full moon is referred to as the Pink Moon.

So, who are you going to believe? The mesquite with its almost pinpoint accuracy down through history? Or the on again off again Pink Moon?

There is also another way to look at it. The actual weather forecast. But even among forecasters, there is quite a difference of opinion. One local forecaster is warning everyone to batten down the hatches, fire up the turbines, and light the smudge pots because there will be a freeze this week on the High Plains. All the other forecasts are calling for lows around 35-38 degrees. So, what is a grape grower to do?

As Texas Wine and Grape Growers Association President Dusty Timmons feels, there really isn’t that much to do to get ready. “If you have your turbines in place and set to come on, or if you have heaters in your vineyards already, all you can do is watch the weather and pray for the best.”

He stated that the first and best protection comes long before the grapes are ever in the ground. “Vineyard placement is so important,” stated Timmons. “Potential grape growers should not choose a low lying area for a vineyard. These areas hold cold air and have no flow in and out for warm air to come in.”

Areas on higher, more level ground are more suited for grape growing in this region. As far as how low the temperature would have to get and how long it would stay at that temperature before damage is done, Timmons feels that it varies shoot by shoot.

“The longer shoots, 8-10 inches out, are more susceptible than those that are shorter. I have seen it get down to 26 degrees and stay there around an hour and no damage was done to the vineyard. On the other hand, I saw a time that the temperature was 29 degrees and all was fine. Then sleet and snow came in, and within five minutes everything on the vine had frozen. There are just too many variables to give an exact answer.”

Another issue that vineyard owners face is wind. Even with turbines in the vineyard, if the wind is too high they don’t run. “If it is cold and the wind is high, it does away with any inversion layer in the vineyard, which work with the turbines to keep the temperature at a constant.”

Timmons also stated that vineyards are not affected by the wind chill. Only actual temperatures are what the vineyard owners look at.

The turbines are usually set to come on when the temperature reaches 34 degrees. They are also programmed to not run if the wind is greater than five miles per hour. “They can run if it is greater than 10 mph. This is just something we have to watch for. If the temperature gets down to 40 degrees, you can bet we will be out driving around to make sure everything is set to run like it is supposed to.”

Meanwhile, work in the vineyard continues, in spite of what the weather forecasters may say. Weeds are being sprayed and shoots are being tied.

Timmons likened grape growing to any other crop grown in the area. There is just not a whole lot you can do about the weather. You just prepare and pray.