From the Vineyard: Managing Winegrape Growth in Unpredictable Spring Weather

26th Apr 2017 @ 05:52 by Matt


By Penny S. Adams, winemaker and viticulturist for Wedding Oak Winery

You know that sickening feeling you get when a storm is barreling down on you, and your car is left out in the elements? You just know that it is going to be pummeled by hail, resulting in a costly trip to the body shop.

Now imagine how you would feel if your entire livelihood was in the path of that same storm? That is exactly the situation Texas winemakers face each spring when extreme weather threatens the fresh growth of grape vines left helpless to the elements in the vineyard. If not a late frost, it is hail, severe winds, or a deluge of flooding rain that threaten our vines.

To make matters a bit more precarious than usual, the warmer than average January temperatures led to the growing season starting out much earlier than normal in vineyards across the state. Having bud break this early always puts growers on edge. The delicate buds are exposed to the risk of late spring frost that can decimate a crop. Additionally, spring storms rife with hail can be particularly devastating in young vineyards where vine trunks and cordons are developing. The earlier in the season when a hail event occurs, the more catastrophic it can be, as the more exposed newly developing buds are likely to be damaged.

Most varieties in the Hill Country are at bloom in their phenological calendar now, and factors like extreme rainfall and wind during this time can impact fruit set, and ultimately yield. In most grape variety blocks, we are in growth phases that range from pre-bloom to just post fruit-set. We are now in mid-season, and the fruit is better protected by larger leaf area acting as umbrellas of sorts.

In spite of the risks, the growing season is going well so far. Several storms have moved through our Hill Country vineyards recently causing limited hail damage to upper canopies and wind damage to canes. I've seen limited damage to Viognier clusters that are just beyond fruit set, so I expect no impact on yield. The storms last week fell in line with our normal "Easter Freeze" events that often plague Texas winegrape production. Several contracted vineyards in the Texas High Plains suffered severe loss of fruit for this season, but fortunately most have been spared.

Spring Planting and Vineyard Management

We continue to plant to vineyard acreage, and diligently maintain our existing vineyards. It’s a busy time in the vineyards.

We have completed spring planting of seventeen acres in our various contracted Hill Country vineyards with Viognier, Trebbiano, Cabernet Sauvignon, Carignan, Dolcetto, Graciano, Mourvèdre, Syrah and Tannat to bolster our production levels for our growing markets. I'm particularly excited about the Graciano and Carignan plantings because these varieties will contribute important complexities to our lineup, especially in our Rioja-style red wines. The nice spring rainfall created a little bit of a dance of sorts regarding getting into the vineyards to plant.

In vineyards planted last year, we are training young vines, which includes developing trunks, cordons and spurs, with frequent vineyard passes during the vines "grand period of growth." During this approximately six-week period of rapid vine growth, they can grow more than an inch per day. As you can probably guess these tender new shoots are especially vulnerable to damage during this critical vine development stage. If damaged by weather, they may need to be retrained from the ground up: a devastating additional expense for vineyard owners.

In our older vineyards we are finishing up shoot removal along the cordons, opening up the canopies to more sunlight and allowing leaves to dry after spring rain. This also allows fungicide sprays to better penetrate the canopies and protect the fruit from the many fungal pressures we have here in the Hill Country during this critical time of the season.

With the early bud break, I predict we will have a slightly earlier harvest here in our Hill Country varieties, particularly Viognier. Despite the vines jumping out of their dormancy early this season, and the minor weather impacts on fruit crop, this 2017 vintage is looking better than ever!