From the Vineyard: Spring Growth is a Crystal Ball to the Fall Harvest
By Penny S. Adams, winemaker and viticulturist for Wedding Oak Winery
If I had a crystal ball, I’d use it to check the weather every day. Instead, like all grape growers in Texas during later winter and early spring, I obsessively check the weather forecasts from all the usual, and less certain, sources.
Even though I don’t have a crystal ball to show me what Mother Nature has instore, the effects of the weather on the grapevines during the winter and spring give us a little bit of a glimpse into what we can expect from the vineyards at harvest.
For the 2018 vintage, my assessment is so far, so good.
Fortunately, winter in the Hill Country brought us little heartbreak this year. Temperatures remained consistently chilly, rather than swinging from one extreme to another. This allowed the grapes to stay dormant until a normal bud break schedule. Our Viognier was first to emerge from dormancy, while the Mourvèdre peeked out last, true to form. Despite the relatively calm winter, a few of our weaker vines experienced cordon (aka permanent wood) loss because temperatures plummeted to the single digits for a few days. However, we had little total vine loss this season.
The advent of spring brings its own unique stresses in the vineyard. As the weather warms to about 55 degrees Fahrenheit consistently, the vines emerge from slumber and use carbohydrate stores to synthesize new shoots laden with potential fruit clusters. A sudden cold snap can kill these shoots — even the whole vine — causing massive fruit loss. What’s more, Texan storms, usually accompanied by strong winds, can result in shoot breakage and irregular cluster pollination. While a little rain is welcome, particularly because we need to irrigate to replace depleted moisture levels soil levels, too much water causes grape growth to get out of hand. That is something we don’t want.
The period after bud break is referred to as the "Grand Period of Growth," a time when many factors come together to determine size of clusters, fruit quality, and wine quality potential. It may seem counterintuitive, however limiting excessive shoot and leaf growth is necessary during the growing season. Pruning shoots and leaves allows the sugars created by the plant to localize mostly in the fruit. It also helps the plant to focus on ripening the berries rather than diverting energy to overall growth. Riper grapes=more sugars=more alcohol, which helps enhances the expression of desirable flavor and aroma compounds. Picking at the right acidity and sugar levels helps us build an exquisite flavor profile. A win for a winemaker.
Some grape varieties, like our Viognier, are naturally predisposed to produce too many buds, and thereby more fruit than the variety can fully ripen. Consequently, we must work harder to remove excessive shoots to achieve a highly-coveted, perfect “fruit-to-leaf ratio” that will ultimately result in superior grape quality.
While surveying newer vineyards planted in 2016, I happily sense the potential for fairly high yields and wine quality. With these vines, there is sufficient light penetration into the vine canopy to ripen this first crop to perfection. In their youth, we place specific importance in training these new vines, promoting the formation of trunks, cordons and spurs so that they can withstand Texas weather conditions.
In the older vineyards, we are removing unwanted shoots and spacing them to encourage sufficient airflow, which helps prevent fungal infections. Two rainy years have resulted in more insect vectors of Pierce's Disease, a devastating sharpshooter-spread disease that is prominent in the southern U.S.
In addition to managing our existing vineyards, we're also working with growers to plant additional acreage.
We plan up to two years in advance for this planting time, ordering vines, preparing the site and carefully planting the vines before the arrival of our Texas heat. At Wildseed Farms, we are planting another 8 acres of Vermentino, Montepulciano, and Aglianico, all central/southern Italian grape varieties adept at withstanding Texas heat. At Fire Oak Vineyard, we are planting 8 acres of Mourvèdre, Roussanne, Grenache, and Sangiovese; most of these are native Rhone varieties except for the latter, an indigenous Tuscan grape.
So far in this growing season, the conditions in our vineyards is right where we want it to be. My prognosis is that we will have a great crop at harvest. We are excited about the potential of the 2018 vintage and can’t wait to bring you more great Texas wine.