'Exploding' trees went viral on social media. How are those trees doing now?
The trees will likely survive, but may face long-term consequences.
Back in January, exploding trees made headlines, following frigid temperatures that took hold of the U.S. Midwest.
The extreme conditions -- with the thermometer hovering around the -30°C mark in some places -- were enough for local meteorologists and newscasters to take to social media to warn of an ‘exploding tree’ risk:
This sounds like a lot, and it can be for the tree, but we do not live inside a Michael Bay film. The trees don't explode into a fiery ball, but an event like this can be quite loud.
This relatively rare phenomenon can occur when it cools down enough for the sap inside a tree to freeze, which then expands due to its high water content. In some circumstances, that creates enough pressure to tear open the bark, accompanied by a loud noise.
Generally speaking, native plants are equipped to handle the cold. Bark provides insulation, and cold tolerance builds throughout the season. But if the temperature drops outside of the norm, or if the air chills before a tree has time to acclimatize, it can cause an 'explosion,' which is also referred to as a 'frost crack,' the National Forest Foundation says on its website.
Frost cracks are also common in spring, due to fluctuating temperatures.
So, what happened to those 'exploding' trees?
On Wednesday, Wisconsin Department of Natural Resources Forest Health Specialist Linda Williams provided an update on the trees that made the news back in January.
"Trees don’t heal wounds the same way that people heal wounds. Instead of repairing the damaged cells, trees compartmentalize the damaged area, serving to limit the ability of bacteria and fungi to invade. Trees then begin growing callus tissue over or around the wounded area," Williams writes.
"How trees respond to wounds can vary based on the species of tree, its health, the location and extent of the wound and any further stress the tree might face during the upcoming growing season."
While a frost crack can permanently damage a tree, it likely won’t kill it, the Government of Manitoba says. Cracks typically heal over the summer, but can reopen in the winter. Repeated cracks, followed by healing cycles, can cause the formation of a permanent scar called a “frost rib.”
The cracks can also leave the tree more vulnerable to wood decay organisms.
In other words, as Williams writes, a tree that has 'exploded' can face long-term consequences.
Example of a frost rib on a green ash tree. Damage apparently occurred years before the photo was taken. (Government of Manitoba)
"If the cracks that occurred during the winter compromise the structural integrity of trees near your home, garage or other areas of concern, you should have them evaluated by an arborist. Some trees may need to be removed for safety," Williams writes.
She adds that cracks in trees generally shouldn't be sprayed with wound paint, although there are exceptions.
"For instance, wounds that occur on oak trees during the high-risk period for oak wilt transmission should be painted immediately."
Header image: File photo via Canva Pro.