Answer: What a beautiful tree! Unfortunately based on your description I am not sure what you have found on the leaf and with willows there is quite a range of possible causes, some more benign and some more serious. You might wish to take a sample to your County Extension (375-5876) for a positive identification and suggested controls. I hope it is nothing too serious. In the meantime, be sure to continue to give that tree ample water while it is becoming established.
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