Grandmother Maple does not have any leaves on her. No big surprise there, its mid-February in Wisconsin. But. My basswood still has leaves in various places, as does the Ash, Sugar Maple, and Red Leaf Maple along with a number of other trees in my neighborhood.
Way back in November, as neighbor after neighbor raked their yards for the third and fourth times there were questions thrown over to the fence as they leaned into a break – ‘why are there so many leaves on the trees yet? Am I going to be raking in December? Is this just a regional thing?’ At the time I did not have any questions, mostly because I rake the yard once and let Nature do her thing and whatever she wanted to drop on the lawn after that was ok with me.
But now it is late winter and still many leaves are clinging to their trees. Now I have questions.
I called a couple people, did some research and found the leave retention in trees is nationwide, so that answers one question. I did see some frustrated individuals brushing/blowing leaves in early December. One has to wonder if they realized it would be snowing soon but at any rate it answered question number two. That left only one question. Why are those darn leaves still on those trees? Here’s the scoop.
The days gradually become shorter and cooler in fall. But it was a bit different this year in that, while days became shorter there was no gradual temperature drop – it went from the 60’s to 20’s (F) in a span of 24 to 26 hours…somewhat nationwide (northern US where leaves of deciduous trees turn color and fall to the ground, hence the raking). This ‘overnight ‘ drop in temperature prohibited the formation of a little known membrane called the abscission layer which effectively seals the leaf from the twig, allowing the leaf to die and fall to the ground. The leaf, never being sealed off from the twig caused the leaves to hang on trees. I was told that when the leaf buds begin to push out in spring, these leaves will fall. And I suppose someone in my neighborhood will be raking in spring to thwart any gossiping of an ill-kept lawn and lazy lawnmanship. Some biologist say it will happen again since our climate is changing and temperature swings are becoming the norm rather than the unusual. Others science partners are not convinced, but they are basically not convinced the climate is changing. All I can say to that is nothing I can really print here.
So there are the answers to the questions that plagued the fall gardeners, rake-leaners and lawn perfectionists earlier in 2017. And into 2018 I suppose.
I had theories but I never thought to blame the abscission layer (mostly because I never heard of it). It does serve to remind me of all the tiny things that need to be in place to keep everything and everyone in balance. Mother Earth is an amazing gal.