Generally speaking, trees belong to either the deciduous or evergreen categories: either they grow and lose their leaves on an annual cycle that sees buds in the spring, lush green growth in the summer, beautiful foliage hues in the autumn and bare branches in the winter; or they have needles or waxy leaves that stay green and attached to the branches all year. Sometimes, though, a leafy tree holds onto its leaves throughout the winter, keeping itself adorned in dried brown remnants of its summer foliage. As a tree owner, you might wonder: is this something that indicates a problem with the health of my tree? And what should I do?
What It Means When a Tree Keeps Its Leaves Through the Winter
There is a stark beauty in bare, winter branches. But there’s something kind of wintery and even a little spooky about the rattle of a winter wind through the dead leaves clinging to the branches of a dormant tree. Why do some trees hold on, and others let go?
Believe it or not, even as experienced arborists, we don’t really know why some trees keep their leaves through the winter (and that’s not just us here at Tree Images — this is an area of ongoing research that doesn’t yet have a definitive answer). There’s some speculation that trees hold onto leaves to repel hungry foragers, such as deer, through the winter, since the bitter taste of dried leaves might keep these tree munchers at bay, protecting the bark and the buds of the trees. Other theories include a benefit to the tree to holding onto these last autumn leaves until the new buds push them off the branches in the spring — the fallen leaves then produce an immediate food source for the tree, right at the vital moment of spring growth. Or maybe these leaves act as a layer of insulation to protect fragile new buds against the last frosts of winter?
Which Types of Trees Are Most Likely to Hold Onto Their Leaves?
Not all trees are equally likely to hold onto their leaves through the winter, and the type of tree is a bigger determining factor in this behavior than geography or climate. Ash trees almost never retain their leaves through the winter, while oak, beech and maple trees are likely to, and all trees that hold onto their leaves are more likely to hold onto them on their lower branches than further up the tree. There’s a slight increase in this holding onto dead leaves (officially known as “marcescence”) in colder climates, but the tree species is a greater indicator of winter leafiness than even the colder temperatures. Younger trees are also slightly more likely to keep their leaves through the winter than older trees.
When Should I Be Concerned?
As a general rule, seeing that your tree has retained its leaves throughout the winter is not a cause for concern, especially if your tree is otherwise healthy. On the other hand, if the leaves don’t fall off of the branches as the buds start to emerge on your tree’s branches in spring, this might be a sign that your tree is struggling, and it might damage or impede new growth. Of course, anytime you feel like something is “off” about your tree, it’s always a good idea to call in an experienced professional like your trusted, local tree service company here in Cincinnati, Tree Images. It’s also good practice to have your trees trimmed and inspected once per year (late winter is the ideal time of year, so if you ARE concerned about your tree’s winter leaves, this is the perfect opportunity to have us out to take a look at it). We’ve got the experience and expertise to handle all of the trees of the Cincinnati area, and we’ll be able to let you know how your trees are doing while we set them up for success into the spring, summer, and beyond.
