A couple of weeks ago, local temperatures fell well below zero degrees Fahrenheit. As with much of the country, during the holidays, night time temperatures plummeted to record lows. By chance, that same week, I happened to overhear a phone conversation between one of our younger staff and a concerned tree owner.
Evidently, the symptoms the caller described to our arborist led him to believe their tree suffered a frost crack. He reassured the caller not to worry as frost cracks normally cause only superficial damage and rarely presents a serious issue for trees.
I overheard him mention the tree was a sycamore. At the mention of sycamore trees, distant alarm bells went off in my head. Thirty years ago, during a similar stretch of severe weather, most of the sycamore trees across town literally exploded. As a species, sycamores retain a great deal of water. The water within the wood can freeze to the point where the expansion in the wood cells causes tree trunks to burst.
Fissures, splits and cracks ran up and down hundreds of city trees. Many of them split open so far you could see completely through 30-inch diameter trees. I remember feeling like I was living in the Yukon or in a Jack London story.
Several residents called us that winter wanting to know if their tree would survive or if they were in danger of falling. Having never seen anything like it before, we were, at first, unsure what to say. We proceeded to examine each and determined that some of the trees should be removed. Others we recommended the trunks be bolted, which, in essence, meant screwing them back together again.
Most of the trees, however needed no help, and when the temperatures warmed to a balmy positive 15 degrees, the fissures unexpectedly snapped shut. The trunks slammed back together so violently it sounded like gunfire. The police actually received so many calls about the so-called gun battles that a public notice was needed to reassure citizens.
Thirty years later, one can still see the vertical seams in the bark of those sycamores. During colder winters, the seams separate slightly, just not as far as that first time. If you hadn’t been there thirty years ago, you’d never know those trees suffered such trauma.
I gently interrupted my associate, explaining to him that the caller’s problem could be more serious than a mere frost crack. I asked him to ask how deep the crack was. When he asked them, they said the crack was, indeed, 10 inches deep.
The brief conversation was a reminder to always, always go see the tree. Medical doctors never diagnose patients over the phone. Neither should we.
Read more: Don’t Diagnose Tree Diseases Over The Phone