lilacs:

It sounds as if your cherry tree is suffering from bacterial canker, which is common on mature stone fruit trees. Development of this disease can be retarded, but not cured, by dormant sprays with a strong copper solution. If the canker begins to kill branches, cut them off promptly and dispose of them. The tree may grow new ones, and soldier on for quite a few years before the disease finishes it off.

If you don't like sour cherries and don't use them, however, one can wonder why you keep the tree at all. Sour cherries are wonderful for pies, crisps, and sauce, but require a little sugar to make them more palatable and bring out their flavor. Some hardy souls, including children, like to eat them right off the tree in spite of their tart character. We pit and process around 20 quarts of sour cherries for freezing every spring, but you do have to have a cherry pitter to make this practical.

Don Yellman, Great Falls, VA

Could this canker spread to my peach tree, which is about 20-25 feet away? The peach tree looks healthy and is certainly producing plenty of peaches.

I hate to cut down a perfectly good tree. The birds enjoy the cherries, even if I don't. Next year I may do something with them. I'll make pruning off the dead branches a priority. Thanks for the info.

Lilacs:

Of course it is possible for bacterial canker to spread to other nearby stone fruit trees, but whether or not is actually will is impossible to predict. My own belief is that a healthy tree is able to fight off canker pretty well, but dormant spraying with copper, preferably twice in the dormant season (early and late) is a good practice, whether or not there is proven canker around or not. Diseases of this type are always easier to prevent than to cure once they are established.

Don Yellman, Great Falls, VA