Several things could causing your cherry tree’s leaves to yellow and fall: The weather has been so unusual this spring and summer with so much rain, that your tree may have gotten too much water.  Cherries like a good soak once every one to two weeks, and anything more could cause your problem.

There are several other possible causes shown on this page from the Michigan State University Extension Service.

Michigan is an important cherry-producing area, so the issues on this page would apply to commercial growers as well as some home gardeners. A viral disease called cherry yellows is a possibility. Another cause could be bacterial canker. 

There are a number of other possible causes, as well, so further research is necessary to determine your problem.  We suggest you call Westchester County Office of the Cornell Extension Service about problems for your area.  The phone number is (914) 285-4620.

Courtesy of NYBG Plant Information Service