To all those with trees that drop leaves or other dry fruits etc on the yard. Mulching deck and blades on your mower fixes that quickly. Good for the soil and much better than raking. Even sweet gum balls get ground up.
Red cedar get my vote for the absolutely worst tree. I'm sure you have heard of the huge fires in OK the last few years. Most have been fueled by those things. In hot weather they burn easily and intensely and grow touching one another if not controlled by the landowner. They create a dense shade that prevents grass or anything else from growing. Mile after mile in some areas, covering hundreds of acres. 50 years ago they weren't found East of I35, now they are spreading like crazy as birds eat and spread the seeds.
Not a yard tree usually, thank God, but a huge rural issue.