The back seat of my car boasts more wardrobe options than my closet. There's the Mr. Rogers-esque cardigan sweater that is perfect for days when the temperature nears 60, my rain jacket and a hat with flaps in case a thunderstorm pops up, and my winter coat, gloves and boots, which have been around for a few years but are still novices when it comes to trudging through snowdrifts.
As bewildering as my back-seat choices can be, nothing is as confused as the pear tree in our backyard. I planned to rake all its leaves into the street for village pickup before Thanksgiving, but now I'm concerned that the tree thinks it is September. There is a touch of yellow, and many of its leaves are still green. The Christmas season is supposed to feature the Christmas song "Greensleeves," not green leaves. Turns out my tree isn't the only freak of nature.
"We are getting those calls: 'Why are the leaves still on my tree?'" says Doris Taylor, veteran plant clinic manager for the Morton Arboretum in Lisle. "We get one or two a day."
The short answer is, "Nature is messing with us," Taylor says. But, as is the case with trees, we get a better picture if we go back to the root of the issue.
"We're going to go all the way back to spring," Taylor says. Our wet spring gave trees lots of leaf growth, producing lush trees for the summer.
Then came "undulating temperatures," a dry August and September, and some wet and warm periods through October and November.
"For two to four months, we were doing all this up and down," Taylor says, explaining how the trees react to whatever the weather brings them. "We've just sort of jacked them around since August."
Trees and other plants take their signals from nature. With favorable growing conditions, "plants kept producing their chlorophyll," Taylor says. Thus, plants continued producing green leaves instead of shutting down for the winter. Our first frost turned some of those leaves a grayish-green, but the higher temperatures kept the greening going.
Leaves that stick around into the winter mess up our raking schedule, but they don't hurt the tree, Taylor says. Some tree species, especially oaks, "can do this and hang on to the leaves until spring."
She refers to an article written by Andrew Hipp, Morton's plant systematist and herbarium curator.
"Most leaves abscise (fall) from deciduous trees in autumn. But, at about the time of bud-break in the spring, many oaks, beeches, and other woody plants go through a second phase of leaf-fall," the article explains. "The desiccated leaves that persist on the tree through winter are called marcescent leaves, and this phenomenon of deciduous leaves persisting past the end of the growing season is called marcescence."
In the meantime, some plants, such as forsythia, might start to bloom during our recent warm spells. Whatever happens with the leaf-hoarding tree in my backyard in the coming weeks, it won't bother the tree come spring.
"You've already got your buds formed for next year," Taylor says.
Instead of raking leaves to the street for a November pickup, we can push them into flower beds, where they are "black gold" that serves as a natural mulch and then adds nutrients as the leaves compost, Taylor says.
So don't worry about our tardy trees hanging on to those leaves. Be grateful that we can welcome the start of December without having to rake leaves or shovel snow.