A week of steep temperatures put vintners on the precipice of irrigation – only to get relief from a cooling trend
(June 1, 2020) Placerville, El Dorado County, CA – Amid the tangle of covid-19 restrictions and reopening guidelines, farming must go on in El Dorado wine region. Across the AVA, vintners considered last week’s high temperatures as they looked ahead to a cooling trend – a vigilant stance among the first evidence of bloom on the AVA’s lower elevations, in a region that farms from 1,20o to more than 3,000 feet in signature granitic and volcanic soils.
Vineyard manager Chuck Mansfield of Goldbud Farms remarked, “Last week’s warmth pushed vines of all varieties below 2,000 feet elevation into bloom. The Camino/Fruitridge (Apple Hill) region’s bloom is still holding off for the moment. We have only irrigated young vines on granite soils so far. We’ll wait for a little more ground moisture depletion before we irrigate most of our vines.”
Derek Delfino, vineyard manager at Edio Vineyards at Delfino Farms, weighed in as the heat spiked: “Basically, evapotranspiration will increase with the higher temperatures. The heat will cause the vines to respire at a higher rate, which means they will lose water quicker and the water that is stored in the soil will be used up faster. Also, the increased temperature will cause the water from the soil surface to evaporate quicker, so even more water will be lost through that. With higher evapotranspiration, the vines should probably be monitored for water stress sooner than usual, and if they are stressed beyond a certain point, then some irrigation should be done.”
Paul Bush, owner/winemaker of Madroña Vineyards, isn’t sweating anything yet: “We are just barely, barely starting flower, so no worries there. (Intense heat during flower can damage the fruit set.) I think the heat (combined with the 3 inches of rain we had recently) is really providing some push for the vines’ vigor, which is great for our older vines. At the same time though, the ‘cover crops’ (weeds) are loving it too! We did speed up work with our weed knife to take advantage of the heat stressing the weeds after severing their roots. As for the crew in the vineyards, we work the mornings tucking and suckering vines and then outside the winery in the shade in the afternoons, cleaning up and hopefully preparing for some time when tastings return to ‘normal.'”
Tom Sinton, owner/winemaker at Starfield Vineyards, is appreciative of El Dorado elevation: “Well, this last week should remind us why El Dorado has such special terroir. It was 93 degrees at Starfield at 2,400-feet elevation, versus 105 in Folsom (a few hundred feet lower) and reportedly 98 in St. Helena. So, frankly, it’s great growing weather for grapevines up here.”
El Dorado AVA, established in 1983, is located one hour north of Sacramento and one hour south of Lake Tahoe. High elevations and cool air drainage from a confluence of rivers, provide a matrix of small premium growing areas that mark its distinction as one of California’s unique wine regions.