Why does my maple tree have black spots this fall? Why are there still lots of seeds and leaves still on the tree?
Isabella County Michigan black spot
Deciduous trees are programmed to drop their leaves after a series of events take place. First, in the fall, as the sunlight becomes less intense, the chlorophyll in the leaves breaks down and the leaves change color. At the same time a row of cells grows across the base of the leaf where it attaches to the stem. Once this row of cells crosses the entire leaf stem, it cuts off nourishment to the leaf causing the leaf to die and fall off. However, this can be influenced by the weather. If there was an early cold snap, before the abscission layer is complete, the leaf may die without falling off the tree. The leaves will fall away during the winter. I’m attaching an article by the USDA which explains the process. https://www.usda.gov/media/blog/2018/09/21/did-you-know-fall-color-begins-spring
I hope this helps.