April snow catches spring, fruitgrowers by surprise
Consider yourself lucky if you woke up late Saturday morning to find snow on the tulips.
Sleeping in, lingering over a cup of coffee and marveling at the beauty of winter’s final fling wasn’t an option for most of the valley’s fruit growers.
Most of the orchardists and grape growers were up well before dawn several times this past week after frost alarms sounded in the wake of below-freezing temperatures.
Temperatures in downtown Grand Junction hit a low of 26 Saturday morning while the National Weather Service reported a low of 24 near the airport.
That set a record low for the date, breaking the previous mark of 27 from 1909.
Neal Guard on East Orchard Mesa reported temperatures in his vineyards and orchard Sunday morning dipped to 28, right at the critical point where damage might occur if temperatures stayed cold long enough.
Granted, it doesn’t take much to freeze a grape bud no bigger than a pencil eraser (you do remember pencil erasers, don’t you?) but brief periods at what growers consider critical temperatures might not harm the bud enough to kill it.
“It just kind of depends on how much of the bud is sticking out,” said Jenne Badwin-Eaton, winemaker for Plum Creek Cellars in Palisade. “Right now at the winery our buds aren’t pushing much but on East Orchard Mesa they are a little bit farther ahead.”
As it’s been explained previously, each grape bud actually is three buds. The cold may kill the primary bud and leave the secondary bud unharmed.
The second bud will produce grapes but 50 percent to 75 percent fewer than the primary bud, according the state viticulturist Horst Caspari.
“There are fewer bunches and they tend to be smaller on average,” he said.
The tertiary bud produces only leaves, which are needed to reinvigorate the plant but don’t make very good wine.
The confluence of several somehow-related factors might have saved this year’s grape crop.
First, the weather over the past couple of weeks has been unseasonably cool and wet, even though the valley continues to be well below average year-to-date precipitation.
Those cooler temperatures helped delay bud break, which three weeks ago seemed ready to happen but the process slowed considerably when warmer weather never arrived.
Second, while Friday night was notable for the lack of wind, which contributes to cold air pooling in low spots, Saturday night many growers reported a steady breeze.
That keeps the cold air moving and mixes the various levels of air (think of how and why a wind machine works), keeping temperatures from dipping as low as they might had the wind never appeared.
“That first night was dead calm and I think everyone had their wind machines going,” said Baldwin-Eaton, who added it was too early to assess any possible damage.
Caspari said temperatures varied widely across the valley, with temperatures in the eastern part barely dipping below 30 degrees Saturday morning.
“Looking at what we’ve seen, most of the growers there didn’t have any reason to run their wind machines,” he said. “However, I can find vineyards where I can find 11-12 degrees temperature changes from one end to the other.”
Also, the timing of the deepest cold is important.
Similar to putting soft ice cream to harden in the home freezer, it takes a while for cold to affect the entire bud.
Even if temperatures were to drop below the critical point, if a grower cranks up the wind machine in time - and there’s a strong enough inversion - it may raise temperatures enough to prevent damage.
If you’re up all night waiting to start your one wind machine, you have a fighting chance.
But if you’re like fruit growers Bruce and Charlie Talbott, it may take you an hour to get all your machines going, which means you have to do some triage deciding which machines to start first.
“The hardest thing was, it was three nights in a row,” said Baldwin-Eaton. “You somehow expect to get one night but three makes for a lot of sleepless nights.”
Thirty years of weather data say April 23 is when the last frost hits the valley but Caspari said this is the fourth consecutive year that a frost has hit after that date.
“It was the second of May in 2008, last year and this year and April 27 in 2009,” he said. “It was definitely colder on Sunday morning than Saturday morning. My cabernet franc grapes are fried.”
Cabernet franc buds out a week or more before some other varietals, including cabernet sauvignon. That leaves the cab franc susceptible to late frosts, particularly this year when the buds had pushed 4-inch shoots just prior to the freeze.
“I don’t think anyone had bud break” on their cabernet sauvignon, Caspari said.
Overall, the late freeze bodes ill for most of the valley’s fruit crop, Caspari said.
“In my 11 years here this is the first time I’m seeing this type of damage to our fruit crops,” he said. “We’ve never lost our apples in the years I’ve been here but this year the apples are gone, the apricots are gone and we don’t know how bad the peaches were hit.”
He said the research station on Orchard Mesa is located in one of the colder areas of the valley and that other growers may not have suffered the losses seen at the research center.