Risks of winemaking grow in the cold
Doug Neam looked at the merlot vines stretching across his property on East Orchard Mesa and pondered his good fortune when he stuck his first vines in the ground.
“I planted these in 1994 because I figured merlot was a varietal in demand and I knew it did pretty good over here,” said Neam. “That first crop was really good.”
Neam soon added to his merlot and a few years later expanded to a nearby south-facing slope where he planted cabernet sauvignon and cabernet franc.
Both the latter grapes also do well in the Grand Valley, although Neam, as are many western Colorado grape growers, is learning that not all vineyard property is equal.
Like many vineyards around the valley, Neam’s vines are spread across a rolling piece of land that falls off on either side. Such hillside vineyards are considered prime lands because the slopes shed the denser cold air.
Whether he did so intentionally or fortuitously, Neam planted his first merlot on a north-facing slope that falls off to a county road winding across the expansive mesa, providing an open alley of escape for the cold air.
Air flows like water, with the coldest settling to the lowest places, like cold water in a pond or your bathtub. Anglers know that the water issuing from a dam stays around 42 degrees year round, which means in the winter that water may be warmer than the surrounding air.
But it also means trapped air, which doesn’t freeze but may well below freezing, can kill tender vines, fruit trees and other plants.
Give that air or water an escape and it flows away, letting warmer air (water) take its place.
However, Neam planted cabernet sauvignon and cabernet franc where his land dead-ends at a neighbor’s brush-choked gully, a shrub dam that stops cold air and forces it back up to almost midway on the slope.
That stagnant lake of cold air, formed during the deepest freeze earlier this month, damaged the vines to where state viticulturist Horst Caspari warned Neam he likely won’t get a crop from those vines in 2013.
“You’ve probably lost everything on that low end of the vineyard,” Caspari said during a recent visit to Neam’s vineyard. “You can see where the cold air pools and it’s like there’s a line where your vines are dead.
“Above that line, you’ll probably get some grapes.”
This cold-weather line of demarcation is a phenomenon that Caspari finds all-too-often across Orchard Mesa where the best agricultural lands often are bordered by dense jungles of growth.
Those ravines, gullies and watercourses are key to proper air drainage, and their existence is part of the reason for the many different micro-climates on Orchard Mesa and East Orchard Mesa.
On a recent tour of cold-struck vineyards from 32 Road to Palisade, Caspari time and again pointed to low spots where vines have been blackened by cold air stopped by wildland growth.
“You can almost see a circle of dead vines where the cold air sits,” he said at one stop, waving his arm to delineate an imaginary high-water line of cold air pooled along the low end of a vineyard. “I’m sure they lost everything in that circle, and the obvious thing would be to put a wind machine right there, to keep that air moving.
“But do you see any machines around here? Not one.”
Neam is fortunate, for he still has some open, south-facing acreage to plant more vines where the gentle, unclogged slope promises better air drainage.
Other landowners, particularly those late arrivals to grape growing, are not so lucky.
“I always recommend they come talk to me before they plant their vines but often that doesn’t happen,” said state enologist Steve Menke during last week’s VinCo conference sponsored by the Colorado Association of Viticulturists and Enologists and the Western Colorado Horticulture Society.
“Too many times, someone walks into my office and says, “I planted five acres of merlot but they aren’t doing very well. Can you help me?’”
“If they had come to us before they planted, I could have helped them with site selection,” he said. “Now, I have to tell them they spent a lot of money on a site where grapes won’t grow.”