by Andrew Chalk, Senior Writer, Texas Wine and Trail May 16, 2014
On a visit to the Texas High Plains last week the biggest story was ‘the frost that failed’. Despite temperatures down to 24⁰ which created the third worst frost in 67 years of record keeping, those growers who took defensive measures saved much of their crop. Veteran High Plains wine consultant Bobby Cox put 2014 in context: “A replicated variety evaluation trial was planted 1974 at the Texas Agricultural Extension Center in Lubbock. Date was obtained for 17 years from 1976 to 1992. A frost as bad as 2014, 2013, 2011, 2009 or 2007 was not observed in that time period.”
The countermeasures went to lengths hitherto unprecedented in the High Plains. Several vineyards burned hay bales between the vine rows and some of these hired helicopters, at rates between $450 and $750 an hour, to hover for hours above the vines in order to drive the hot air of the burning bales back down. Helicopter pilots came from as far away as Houston and Dallas such was the demand.
Perhaps the biggest long-term commitment to Texas vineyards was at Lost Draw Vineyards where owner Andy Timmons had purchased four giant wind machines at over $30,000 each to circulate air and prevent cold air settling on his vines. Each of these machines, powered by a 186HP Ford V-10 engine, started automatically and ran for hours pushing air around, covering 8-10 acres. The results were dramatic. Below on the left is a picture I took on May 8th of Viognier grapes from a part of the vineyard that was not within the range of any of wind machines. The crop loss is 80% and the vine growth is attenuated. On the right are some Viognier grapes (of a similar age and from the same vineyard) that were within range of the wind machines. They are green and vibrant and there is no crop loss. Timmons says he believes the machines saved his crop and he plans to expand their use.
While wind machines are commonplace in vineyards on the west coast, this is the first time that they have been used in Texas. A demonstration so impressed Chris Brundrett, winemaker at William Chris Vineyards in Hye, Texas that he bought one for his Hill Country vineyard. I spoke to Dave Harmening, a sales representative for the manufacturer, who said that the air circulation can essentially grab a few extra degrees and, if temperatures do not fall below this, save a crop. The machines are used not just in vineyards, but extensively in fruit orchards, especially in Washington and Florida.
At other vineyards, growers used a less expensive version of the fixed place wind machine, running fans driven by tractor engines. Others carried lighted hay bales around on flatbeds between their rows of vines.
Another novel approach was used by Bingham Family Vineyards, one of the largest growers in the area. They gave the vines a high nutrient diet (with special attention paid to zinc) and packed nutrient-rich soils and compost around the base of the vines in order to increase their resistance against frost.
The significance of these measures when considered together is that they reflect the increased value of the Texas wine crop. Just a few years ago, it would not have been worth while to make these investments to prevent frost damage. Also, the growers report that these measures work. That means that the biggest bane of Texas grape growing may have been overcome. That is a game changer.
There is no one who doubts the quality of the Texas grape crop. The problem has been erratic quantity. One (or more) out of every four years the harvest is severely depleted by frost. As a result, grape output over time fluctuates erratically like a high amplitude sine wave. These countermeasures have the effect of eliminating the troughs in that wave and so damping those fluctuations, possibly drastically, by eliminating the low output years. As a result, the supply is more consistent and the total output much greater over time.
Of course, other problems like hail and drought still exist. The point is that these are second order compared with the damage from late frosts.