Extreme Cold Temperatures Trigger Tree Damage Phenomenon

Arborist Debunks Viral Claims of “Exploding Trees” During Cold Weather

Social media posts warning about “exploding trees” during extreme cold snaps are creating unnecessary concern among residents, according to a Cedar Rapids tree care expert.

Ashley Whittlesey, owner of That Girl Tree Care, says the phenomenon being described in these viral posts is actually a natural condition known as frost cracking, not the dramatic explosions suggested online.

“When I heard that, I kind of giggled,” Whittlesey said. “I’ve never heard the term ‘exploding trees’ used professionally.”

Frost cracks occur when sap inside trees freezes rapidly during sudden temperature drops. The quick expansion of freezing liquid can create pressure within the trunk, sometimes resulting in visible cracks along the bark. The condition primarily affects trees with softer bark, with maples and lindens being particularly susceptible.

Despite decades of professional experience in arboriculture throughout Eastern Iowa, Whittlesey reports that neither she nor her team has actually witnessed frost cracks in the region. The phenomenon typically requires somewhat warm weather before a rapid plunge in temperature—conditions that aren’t common in Iowa’s more gradual seasonal transitions.

“For the most part, the trees can recover from it,” Whittlesey explained, emphasizing that even when frost cracks do occur, they rarely cause permanent damage to otherwise healthy trees.

The recent viral posts have struck a particular nerve in Eastern Iowa, where residents remain sensitive to potential tree hazards following the August 2020 derecho. That devastating windstorm, which produced gusts equivalent to a Category 4 hurricane, destroyed an estimated 65 percent of Cedar Rapids’ tree canopy and caused billions in damage across the Midwest.

“I had quite a few people reach out to me worried and concerned,” Whittlesey said. “I was just like no, not saying it doesn’t happen, but it is very rare for it to happen.”

The concern reflects a broader pattern of heightened anxiety around tree safety in the region. The derecho’s impact fundamentally changed how many Eastern Iowans view the urban forest—from a source of shade and beauty to a potential hazard during extreme weather.

Tree experts note that while frost cracks are largely benign, they can occasionally provide entry points for pathogens or insects. Professional arborists recommend monitoring any visible cracks but emphasize that immediate intervention is rarely necessary.

For context, legitimate cold weather concerns for trees include winter desiccation (when roots cannot absorb water from frozen soil), salt damage near roadways, and breakage from ice accumulation or snow load. These issues typically pose greater threats to tree health than the rare frost crack.

Climate scientists have noted that while global warming is increasing average temperatures, it can also lead to more extreme weather fluctuations—potentially creating the rapid temperature swings that contribute to frost cracking. However, the phenomenon remains uncommon in most regions of the United States.

Whittlesey mentioned that her tree care company typically suspends outdoor operations when temperatures drop below approximately 15 degrees Fahrenheit—both for worker safety and because frozen wood responds differently to cutting tools.

The viral social media posts appear to be another example of how extreme weather conditions can generate misleading information online. Tree care professionals recommend consulting certified arborists rather than relying on unverified social media claims when concerned about tree health or safety.