Though the sun has been shining and temperatures have been above average so far this winter, Umpqua Valley vineyard managers are optimistic about the state of their future wine grapes.
Misty Firmin, meteorologist for the National Weather Service Medford office, said from Oct. 1 to last Thursday, Roseburg’s temperature had an average of 47.9 degrees, making it the 13th warmest winter since records began in 1930. The warmest on record was 51.6 degrees in 2015.
So far in February alone, the average temperature has been 52.8 degrees.
Steven Williams, property manager and supervisor of Glaser Estate Winery in Roseburg, said the spring-like weather has the potential to start the growing season a little earlier than expected.
“The fruit trees are already starting to bloom,” Williams said. “It’s kind of hard to tell what’s going to happen because it’s still February, but things are moving on quicker than normal in comparison to the last few years.”
Steve Simmons, co-owner of Misty Oaks Vineyard in Oakland with his wife, Christy, said the mild weather has been good for the vineyard so far.
“Temperature turns the grapes on so they’re way ahead,” Simmons said. “For us it’s kind of a good thing because we’re on a hillside, and usually we can’t get mechanized equipment in this early because it’s wet, but this year we’re already in.”
Earl Jones, owner of Abacela Winery near Roseburg, said this mild weather really has no negative impact as long as the grapes are already dormant. Fortunately, he said, his vines did grow dormant in November when temperatures dropped to around freezing.
The three vineyard managers said they have already begun pruning their vines and have not seen any early budding. When vines begin pressuring up as they’re doing now, they bleed when they’re pruned, which Simmons said helps protect them from spores that could develop and hurt the plants.
“We’re still planning on having a banner year, but we just got an earlier start on pruning than we did last year,” Williams added. He began pruning about three weeks earlier than usual.
However, all three vineyard managers said if the buds do come out early, they could be damaged if temperatures drop back down to freezing.
According to Simmons, wine grapes in the Umpqua Valley generally begin budding in mid-April, but an early bud break could occur around mid to late March.
“I haven’t seen any budding yet, but I’m a little concerned because of the warm sunny days we’ve been having,” Jones said. “We don’t think about the vine budding out or showing any of its seasonal growth to develop until the temperature becomes a consistent average of 50 degrees.” The cooler nights ranging around 40 degrees have kept the vines from growing so far.
If an early bud break does come without any freezing days, it could mean a long growing season for the grapes.
“Having a longer growing season before it starts to cool off is not going to hurt anything,” Williams said. “It gives us a little bit more time in the season for the ripening and for the sugar levels to balance out.”
Simmons said the weather is a mixed blessing.
“It’s nice to be out there early and hope for an early bud break, but there can be consequences and you’ve just got to plan to mitigate those,” Simmons said.
Vineyard owners wary of the winter warmth and the possibility of a subsequent freeze can leave extra buds on their vines in case of damage. If pests come to prey on the vines, the vineyard owners can also spray them with dormant oil, as Williams said he plans to do.
Jones said the vineyards could use more rain, as wetter soil during the winter helps support growth in the early spring, but overall he’s happy with the weather.
Firmin said precipitation this season is significantly below average.
Based on monitors at the Roseburg Regional Airport, the area received 11.52 inches of precipitation between Oct. 1 and last Thursday, which is 10.57 inches below normal. It usually rains about 77 days from October through February, but so far it’s only rained 59 days, much less than the 103 rainy days last year.
“That is a big difference,” Firmin said.
Glaser Estate is a dry farm, meaning it doesn’t use irrigation, but Williams said the vineyard sits close to the river so he can irrigate if need be.
Simmons, however, said his vineyard received enough rain in late October and November after he harvested the 2017 grapes, which will help the vines and potentially lead to a great 2018 harvest.