Chip Murrow had never heard the term “exploding trees” in his 30 years as a forester for the Iowa Department of Natural Resources.
As temperatures drop in Iowa and across the country this weekend during a major winter storm, curiosity and concern about trees exploding from the cold have grown. Google searches for “exploding trees” have skyrocketed in the past month, as viral videos of trees bursting at the trunk have racked up views online.
Is there a danger of exploding trees in Iowa? And how does it happen? Here’s what to know.
What does ‘exploding trees’ mean?
Murrow, an urban forestry program specialist with the Iowa DNR, said the phenomenon is called “frost cracks,” and it’s not uncommon with a sudden drop in temperatures.
“You get a warmer day in late winter, and that’ll start the sap to flow a little bit in the south and southwest side of the tree where the sun’s doing more of its warming during the day,” he said. “When it suddenly gets cold, that will cause the sap to expand and cause a crack in the tree.”
It gets the misnomer of exploding trees because the cracks in the tree can sound like a gunshot, according to Murrow.
He also said that freeze cracks are more likely to occur when the outer wood of a tree cools and contracts more rapidly than the inner layers, or when a tree already has a defect from improper pruning.
What trees are more susceptible to ‘exploding’
Murrow said frost cracks are more common in trees with thinner bark, including maples, birch and sycamore.
“It doesn’t mean it can’t happen in healthy or even thicker bark trees, but it’s more likely in those thinner bark species, especially if they’re younger,” he said.
What to do with ‘exploding trees’
He said that if citizens are concerned about damage to trees on their property from frost cracks, they can call an arborist to “wound trace” the tree and allow the tree to heal the crack’s wound more quickly.
The DNR also recommends wrapping young trees with thin bark in white tree protection wrap during winter to reflect sunlight and help regulate temperature. The paper will have to be removed at the beginning of spring to limit moisture problems heading into the warmer months in Iowa.
Cooper Worth is a service/trending reporter for the Des Moines Register. Reach him at cworth@gannett.com or follow him on X @CooperAWorth.
This article originally appeared on Des Moines Register: Are exploding trees a real thing? What to know about frost cracks
Reporting by Cooper Worth, Des Moines Register / Des Moines Register
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