I live in Maryland, and my Japanese maple is at least 10 years old. Last winter had been very severe and there were some frost days in spring. I noticed that there are much fewer leaves this year compared to previous years. Some branches do not have any leaves at all, and they have a brownish red discoloration on the bark. There are some tiny branches growing low down on the main trunk with healthy looking leaves. What should I do? Should I prune away all branches that have the reddish color? Any suggestions will be welcome!