From the small time/space continuum I occupy on the treadmill at the gym I ponder the natural world. I grab the machine closest to the windows so I can pretend it's a brisk walk in the great outdoors without all the bothersome cold. I gaze out the window at the white woods; the birch trees, the cattails, and an unidentifiable thicket of something. It's there I see the leaf.
It's been there all winter, this one persistent leaf. Curled up and black, I can almost hear the desiccated crackle it must make as the wind prods it on a daily basis. And like a picture that needs straightening, a scab that begs picking, the leaf dares anyone to flick it and tear the fibers that stick it to the branch.
It's not the only one. This phenomenon, when leaves fail to fall, is called marcescence. Most evident on all the oaks around the metro, it's an explainable but puzzling occurrence. At the petioles, the point of attachment to the tree, hormones flow back and forth. As the days shorten and temps fall, the amount of one in particular, auxin, is reduced. The area becomes sealed and a digestive enzyme helps to release the leaf. In fancy science talk, this all happens in the abscission zone.
Yet it doesn't always go as planned in the abscission zone. Although it is not known exactly why, some leaves on certain tree species remain through winter albeit in a brown and lifeless form. It's like they forgot to fall.
I picked up this bit of tree trivia when a former neighbor complained to me that her trees hadn't dropped their leaves and she was dreading the mess come spring. You'd think those leaves would know they belonged in plastic bags come winter! She wanted to know what she could do to make them fall. As one of those homeowners that equate tidy yard care with good citizenry, she was visibly concerned.
After a little research I was able to tell her why they dangled annoyingly above her reach, but not how to force them to say "uncle" and dump the foliage. She was not pleased, and walked away muttering, probably something like, "just what garden does she think she's master of".
Indian legend gives a more romantic interpretation. It is said that the oak trees chose to defy the "stern warriors of winter", Hatoe, the frost god and Hadui, the storm wind; in honor of the sun and summer that gave them life. In spite of all the harsh weather, the oak would rattle his leaves in the face of winter, giving up only when the new buds were ready to break.
And that is what happens, sort of. The new buds break the bond, a polymer-like substance that holds fast the dying leaf through blizzard winds and pelting snow. One by one, I see them floating down, falling on the snow, ready for raking; a sure sign of spring.
Maybe my neighbor would have liked that story better.
(Catch more signs of spring atThe Garden Buzz)