The annual leaf drop indicates the start of fall. The bold yellows, oranges, reds, and browns remind us that it’s that cozy time of year again. The process of leaves falling and growing back is a rhythm we’ve come to know and love. But why do some leaves not fall off trees in the winter, and what does it mean?
In most cases, if a tree is still holding on to its leaves in winter, it’s because of a sudden change in weather, the type of tree you have, or a nutrient imbalance.
At Arborist Aboard, we’ve seen our fair share of stubborn trees, and we know how nerve-wracking it can be. Read on to learn what our tree service experts in Tampa have to say about why your tree’s leaves haven’t fallen off yet.
It’s Too Cold
When the temperature begins to drop during the fall season, this signals a reaction for trees to stop producing chlorophyll. Chlorophyll fuels the process of photosynthesis and is responsible for the leaves’ green color.
This slow reduction in chlorophyll causes tree leaves to turn brown in the fall and winter. It also triggers the cells in the leaf stems to form an abscission layer, “cutting off” the leaves from the tree.
Because the weather plays a huge role in this process, if there is a sudden change in temperature like a cold snap, the cold will immediately kill the leaves. This essentially skips the abscission process, causing the dead leaves to remain on the tree.
It’s Too Warm
On the other hand, the opposite can also be true, particularly in warm climates like Tampa. If it’s still warm and sunny in mid-winter, this can confuse your tree. The leaf drop process is dependent on a drop in temperature, so if it’s still warm out, your tree won’t get the signal to start the abscission process.
It’s The Type of Tree You Have
Sometimes, the answer to “Why do some leaves not fall off trees in the winter?” is that it’s not you, it’s your tree. Certain types of trees are more prone to holding onto their leaves than others. These trees hold onto their leaves throughout the winter and eventually shed them in the spring.
The reason for this is not fully known, but scientists speculate trees do this to provide nutrients to the soil in spring, acquire the moisture from snow during winter, or deter pests.
In the Tampa area, types of trees that are more likely to hold onto their leaves include witch hazel shrubs and hornbeam. If you have one of these trees, just give it time and it will eventually lose its leaves.
There’s Too Much Fertilizer
Overfertilizing your tree can cause your tree to prioritize growing rather than preparing for winter. To lower the nitrogen concentration in your soil, you can plant other plants near your tree or apply mulch.
In any case, your tree will eventually lose its leaves. If it’s otherwise healthy and free of pests, there should be no cause for concern. However, if you’re concerned about your tree’s health or there’s been a significant weather event, consult with an experienced arborist.
Keep Your Trees Healthy – Call Arborist Aboard Today
Still wondering “Why do some leaves not fall off trees in the winter?” At Arborist Aboard, our certified arborists can help you care for your trees properly by consulting on watering new trees, tree pruning, and more.
We provide unbeatable professional tree care services in Tampa, FL, and the surrounding areas. Call us at (813) 920-4410 to take advantage of your free estimate today.
