Before you cut down trees, check to see if they are actually just stressed.
A flash freeze last October that caused temperatures to drop from a balmy 83 degrees one day to 13 degrees the next likely caused internal damage to a variety of trees and shrubs across Colorado, experts say. According to ISA-certified Arborist Craig Miller, a flash freeze causes moisture inside branches and roots to expand into ice crystals, rupturing the plant's cells. A mid-winter drought along with a late-season freeze April 13 caused additional stress to plants and trees along the Front Range, killing many trees and causing visible damage such as brown spots and slow leafing to others.
Widespread tree damage has been a hot topic in many communities, especially where homeowners associations are asking residents to cut down and replace trees that appear dead, but may not be.
Plants and trees that are already stressed by disease, insect infestations, and overcrowding are especially prone to weather-related events, but even healthy plants that are well maintained can suffer damage in extreme weather or winter drought conditions. Both deciduous and evergreen trees are susceptible, although native plants have a better chance of withstanding winter conditions with minimal damage, said Miller in a video produced by Garden Ambassador Luan Akin for Tagawa Gardens about the plight of freeze-damaged trees this year.
So, how can you tell if your tree is really dead or just recovering from winter weather swings?
Miller suggests checking branches to see if they are supple or bendable. If the branch still bends, that's a good sign. A branch that is stiff or breaks when bent may be dead. He also suggests scraping a small patch of bark from a branch. If the bark is green, the branch is still alive.
A tree that is truly dead will have to be cut down, but a stressed tree can recover with good care.
"Don't automatically reach for the pesticide or lay down a bunch of fertilizer," said Akin. "It's entirely possible that damage is environmental—meaning the flash freeze and winter drought."
Here in Colorado we’re used to erratic freeze-thaw cycles, but this year’s were more dramatic than most. We've rounded up sources from the State Pubs Library on how the weather is impacting your trees, yard, and garden: https://t.co/F75jMhsZpK— CO State Library (@COStateLibrary) June 16, 2020
Miller said the best thing homeowners can do to help trees recover is to have patience. Trees can take weeks and even months to return to normal after an early fall or late spring freeze. Adequate watering is also critical to keeping trees healthy all year long, he said.
The Colorado State Forest Service recommends giving trees 10 gallons of water per inch of tree stem (measured 4.5 feet up the tree from the soil) per week during the growing season. Miller also recommends watering trees once per month during the winter months when rain and snowfall are inadequate.