For anyone who hasn’t checked the forecast for the Sierra Foothills recently, I’ll give you the summary – it’s going to be hot! We are projected to experience an unprecedented heat wave that will bring 100-to-105-degree temperatures to our region for possibly 10 to 12 days and maybe longer. While the discomfort of living and working in this type of heat comes to mind, our first thoughts are on the vineyards and what we need to do to ensure the vines have everything they need to ride out this heat wave. Excessive heat is becoming one of the extreme weather events most concerning to grape growers. Some growers primarily in the Napa Valley and Paso Robles regions are having to install shade cloth and the support structure for it into their trellising systems so as to combat warmer temperatures.

For us here at Sierra Vista our preparation Starts long before we see the 10-day forecast with all the heat coming. The most important points of emphasis are, overall vineyard health, canopy management, our irrigation system, and the timing and duration of our irrigations. As for the overall vineyard health we have worked to find any deficiencies in the vineyards and correct with fertilizations, cover crop, foliar sprays, and replacing any diseased vines with young healthy ones. This relates directly to canopy management as the vines canopy is made up of all of the canes, shoots, and leaves that bring in nutrients for the vine, and also provide shade to the grapes. The amount of canopy a vine produces is directly related to the health and strength of the vine. Managing the canopy is working to find the right balance of shoot thinning, leaf pulling, and lateral removal to open up the vines for airflow and sunlight while leaving enough canopy to provide the adequate amount of shade so that the grape clusters don’t get sunburn. The last part of the process is irrigation. Whenever we see dramatic heat temperatures on the horizon, we irrigate the vines 3 – 4 days in advance so that the water is readily available to the roots before the peak heat arrives. When temperatures get over 100 degrees the vines go into a preservation mode and you want there to be plenty of soil moisture available so the vines don’t get overly stressed.

While the daytime temperatures are seemingly hitting record highs, we’re still fortunate being a higher elevation vineyard, where our nighttime temperatures cool down to the low 70s and high 60s. This gives the vines a nice reprieve from the heat. Furthermore, being on top of the ridge we experience gentle afternoon and evening breezes that move the stagnant hot air out and bring cooler air in. All in all, while we would of course want nothing more than a perfect 85 – 90- degree growing season, our vines are resilient and strong enough to make it through these dramatic weather events, and still produce amazing quality fruit. Lastly, this vintage is still shaping up to be one of the best we’ve seen in a long time.