We recently planted 5 Slender Silhouette Sweetgum trees in our backyard. They were put in at the beginning of October. The leaves did not change colour over the last few weeks to the typical brilliant fall colours these trees usually have. There were very few leaves that made a slight change to yellow, however the trees are pretty much entirely green still. Also, none of the leaves have fallen off yet (as of mid-November) – not a single leaf! We saw several other of these types of trees that had started to change and had brilliant red colour by the end of summer – late August to September. I am just wondering why these trees may not have changed colour and why they have not dropped their leaves. We had another tree in the past, at our previous home that did this (was late to change colour and drop leaves in the fall) and this tree eventually died (although it was a different type of tree). I am wondering if this is indicative of a problem with the health of the tree.
Thank you in advance for any advice you can offer!
Hi there and thanks for your intriguing question. I can say we have never had this one! I have had help from another Master Gardener in finding some good references to help you understand what is happening.
While these articles do not directly address Sweetgum trees, some of the reasoning may apply. Consider one of the sentences in the last paragraph of the Adirondack Almanack article. “Some trees may not use their sugars to create red pigments at all. They may, instead, use that fuel to grow new twigs.”
You stated that the Sweetgums were planted in October, after the time you noticed similar trees changing. You didn’t say whether your trees were earth grown or container grown, or what size they are. All of these factors may have played into the trees’ decision to hang on to the leaves. I would not consider the lateness or lack of colour a problem, simply because your trees are in the early stages of adjusting to their new home, and are dealing with their most important job: getting the root systems fully functional before the ground freezes. If the leaves had changed colour early or they had fallen entirely, then the trees would be displaying classic symptoms of transplant shock. As long as they were planted six weeks before the first deep frost, with plenty of space around each one, and they have been watered well, they should be just fine. As you most likely know, they need lots of sun…not that they can get it now.
We would be interested to hear back from you in early June to know how the trees are doing. Please refer to this query.