iSeeChange: A Longer Growing Season

Nov 24, 2015

Harvest is done on the Western Slope.  All the cherries, peaches,  apples, and pears have been picked and sold, and now frost and snow is settled in.  Over at iseechange.org, several people were keeping track of the long growing season and the turn to winter.  

Paonia after a recent snowfall.
Credit Amber Kleinman / iSeeChange

Amber Kleinman of Paonia noticed the first snowfall of this year was a few days later than the past few years.  Marilyn Stone, also of Paonia, noticed the snowfall and thought it might be a little late.  Doug Fritz in Hotchkiss noticed the first frost in late October, remarking that it was an incredibly long growing season.  He’s definitely onto something. 

Zach Schwalbe is with the Colorado Climate Center.  They collect data from stations all over the state, including Paonia. 

“Our average growing season is 153 days with data going back to 1958,” says Schwalbe, “and this year we had a 183 day growing season.”

This year’s summer was 30 days longer than average, but not the longest.  There was 192 days between freezes in the summer of 1987.  Looking at the data from the 50’s shows that climate and weather out on the Western Slope has been ‘swingy’.  Schwalbe does say though that overall, we’re seeing more time between spring and fall freezes, longer growing periods. 

Ron Godin is a soil and crop scientist for the Colorado State University extension in nearby Delta.  He’s also noticed changes in the data.

“Thirty years ago, the last frost in the spring was the first week in May.  Now, it’s on average the middle of April”

Out by him, he’s seen about an addition of 2 weeks on either end of the season.  There’s some good news for growers. 

“We might be able to plant varieties that take longer to ripen,” he says, “like Gala apples – they ripen fairly early.  But Fujis are a long season apple and they take a lot longer to ripen.  Maybe with one more month in the growing season, we may be able to ripen Fuji apples eventually. 

That could open up new markets for growers.  Grain farmers, too, could see higher yields with more time. 

Invariably with climate change, though, there are downsides.  Godin says that with some extra time, insects can breed one more time, creating an extra generation of pests.

“Codling Moth is a good example.  In a really warm year that starts early, we may get three or four generations of codling moth (and that’s the worm in the apple).  In a shorter, typical season, we’d only get like 2 and a half or three.  So we’d have an extra generation of insects.”

There’s also the problem of freezes in the spring catching early flowers off guard, like what happened this year.  More time growing for plants also means more time sucking up water.   Something that will be a challenge, he says, for an area already so dry.