Dave Paricio, a 40-year arborist, is swamped performing house calls for sick, dying trees in the Denver area.

“It really has been the strangest year I’ve seen in all my time evaluating trees,” said Paricio, who is a certified arborist and the assistant district manager of Davey Tree Service in east Denver.

Bark is peeling off. Pine needles and leaves are browning and falling to the ground early. Many trees never produced leaves or fruit. And some trees that are beyond repair are getting the ax altogether.

The root of the problem, according to experts: a sudden, intense temperature drop in November 2014 that damaged trees’ cores before they were winter-ready.

In the early fall of 2014, temperatures were as warm as 80 degrees, lulling the trees into a false sense of season, said Colorado State University extension specialist Tamla Blunt.

Then on Nov. 10, the Front Range received a chilling shock when temperatures plummeted from 58 degrees at 8 a.m. to 16 degrees by 11 p.m., Blunt said. Temperatures stayed frigid for nearly a week, chilling trees and people alike to the core.

At the time, the trees were not finished with the hardening process that enables them to withstand winter weather, Blunt explained. Many were instantly flash-frozen, and some would not show signs of damage until spring.

Cherry trees, elms, maples, willows, evergreens and more are now left battling the wounds they received in the 2014 freeze.

Of the 2.2 million trees in the city, Denver forester Rob Davis estimates that tens of thousands are dead from the November frost.

“We’ve got more trees to cut down in Denver, which doesn’t help our mission,” Davis said. “And we’ve got a lot of trees to replace, which is a big challenge and a resource-sensitive operation.”

Just as the trees were starting to recover, Davis said, a freeze on Mother’s Day hit them while they were down.

“It’s like dipping into your savings account,” Davis said. “If it happens too much, it can be dwindled down, and then all of a sudden you’re left with nothing. It’s more of a ‘death by a thousand cuts’ situation.”

For years to come, Denver trees could be feeling the effects of the devastating freezes, Davis said.

The city assumes an average asset value of about $1,000 per tree and, using that number, Denver estimates a citywide loss of more than $10 million.

“That does not take into account things like property values, air quality, shading and other things that trees typically help with,” said Cyndi Karvaski, spokeswoman for Denver Parks and Recreation.

With the trees in a vulnerable state, common ailments like leaf fungi in aspens and cottonwoods, tussock moths devouring Douglas fir trees and emerald ash borer that have plagued cities such as Boulder could be the nail in the coffin that sends local trees timbering down.

“Several years later, you could see a tree that’s dead that really died because of this November freeze, and something small was its final blow,” Davis said. “I imagine it will be multiple years of downward spirals for these trees.”

Residents with sickly trees are advised to seek the guidance of a certified arborist to set out a game plan, Blunt said.

With a harsh winter likely headed Denver’s way, pruning dead branches, fertilizing and cutting back on water are key to tree revitalization and preparedness, she said.

“You want them to start going into the state of winter readiness,” Blunt said.

Davis said no matter how much you prepare, Mother Nature will have her way.

“If nature is going to throw something like that at you, there’s not a lot of preventative measures that can be taken,” he said. “My biggest fear is getting a lot of snow early on this winter.”

Elizabeth Hernandez: 303-954-1223, ehernandez @denverpost.com or twitter.com/ehernandez