Growers still cautious after December freeze
Unruly stems shoot off in multiple directions, like lightning trapped in the veins of a plant.
Normally, by this time grape vines are close-cropped and orderly, simply awaiting the hot days of spring to burst out of the winter doldrums and turn sunlight into grapes. But this year has been far from normal.
Two frosts, one in October and a double-digit below-zero zapper in December, has made this spring a period of wait-and-see for valley grape growers.
What they’re seeing is things aren’t as bad as they might be but certainly aren’t as good as they could be.
“The good news is it looks a little better than we thought, the bad news is there’s still plenty to cry about,” said Horst Caspari, state viticulturist with the Colorado State University Research Center on Orchard Mesa.
There was concern a few months ago, shortly after temperatures as low as minus 22 degrees were registered in the valley, that half or more of this year’s grape crop might be ruined.
It’s still a bit early to tell the true extent of the damage, Caspari said, and it might take another week of warm weather to tell if the vines are going to have grapes, just put out leaves or none of the above.
“There’s a lot of dead stuff out there,” he said, ruefully. “We’re seeing in our vineyard (on Orchard Mesa) we probably have on the order of 50-percent dead buds. But since we didn’t prune, there are hundreds of (buds) out there to choose from.”
But all buds aren’t the same. Grape buds each are comprised of three separate buds, any or all of which might survive a frosting. Only the primary and secondary buds produce fruit, the tertiary bud produces only leaves.
During walk-about through his vineyards last week, Neil Guard of Avant Farm on East Orchard Mesa was slicing buds, trying to determine how many survived the winter.
“Look, you can see the primary bud is dead but the secondary bud might be OK,” said Guard as he cut delicately into a cabernet franc bud. “I think the cab franc survived the cold. But it looks like the riesling is toast.”
Caspari said cabernet franc is one of the more cold-hardy varietals but it’s also early to bud, making it susceptible to spring frosts.
Gewurtztraminer and chardonnay also bud early, he said, but how well any vines do also depends on where they are located.
“Nancy (Janes of Whitewater Hill Vineyard) said the riesling near her house (off 32 Road) is doing quite nicely and (Parker) Carlson said both his riesling and lemberger are pushing well,” Caspari said. “But we still don’t know if it’s primary, secondary or tertiary.”
The proof will come soon after the next warm spell, Caspari said.
“As soon as we get a couple of days of warm weather, things should really explode,” he said.
A lot of buds started “pushing” (swelling as they mature) this past week when temperatures reached the mid-70s, but the drive to bud shut down when cool weather arrived.
The problem with having buds grow is they become terribly delicate and there still is a lot of pruning to be done. Now, when workers start pruning those long stems, it’s all too easy to knock off the swelling buds.
“You’re always going knock some of the buds off, so when you’re pruning you don’t touch the ones you want to keep,” Caspari said.
Growers like to prune shoots close to the main stem vine, leaving two live buds per shoot. This gives growers an option in case one doesn’t survive.
But this year, because the cold hit vines differently, finding those two live buds might mean going farther out on the shoot.
“I still advise them to trim back to two live buds, no matter where they are,” cautioned Caspari. “It may be high on the shoot but it’s better to have two shoots (each bud can produce next year’s shoot) than have nothing.”
Even if it’s only the tertiary bud that survives, having leaves and a live shoot means you have a plant living for next year.
“This year we’ll be going through the vineyards with one or two or three passes, getting things in the best shape we can and seeing what fruit is there,” Caspari said.
“I’m telling (growers) this won’t be a one-walk-through pruning. Or at least it shouldn’t be.”
Still facing the threat of a late spring frost, fruit growers go to bed each night hoping not to hear the frost alarm.
Do fruit growers ever sleep?
“No,” answered Caspari. “Well, maybe a little in the summer, but then they’re worried about disease and insects. It’s not an easy life.”