Question
I have a 3 yr old willow tree which is developing brown spots on its leaves this fall.  Is this normal or something I should attend to?

Answer
These are leaf spots caused by a fungus disease. I would not be concerned with these. Most leaf spots show up late in the year when the trees are beginning to shut down for the winter. These cause no real health problem to the tree. The best way to cut down on the number of these leaf spots is to rake up and remove from the site the fallen leaves. This will remove the fungus spores and reduce the amount of spots next year.