Question
Some of the bark on our Oct. Glory Maple (planted 4 years ago)has turned black, feels a little slick (almost a greasy feel), and has some cracks in it that are mostly about 1 to 2 inches long. This is mostly on the south side of it.  It is in out front yard with nothing near it or shading it and gets full afternoon shade. we have had a drought all summer and haven't been allowed to use our sprinkler system. I have hand watered it but perhaps not enough.
Is this normal or a sign of fungus disease or what?  What should I do about it. I can e-mail a photo if necessary. Thanks for your input.

Answer
Please send the pictures to [email protected] and I will see if I can ID the problem. Put in the subject line "Allexpert question" that way it will not get sent to a spam file.

Thanks for the pictures. It looks to me like one of the canker diseases most likely Hypoxlion. There are a couple that can infect maples.  Hypoxlion cankers are caused by stress on the tree due to things like drought. There is not really a cure for this disease except to keep the trees healthy and watered. Sorry I do not have a product that can be sprayed on this and control it.

A tree needs about 1 inch of water per week. During the drought and restrictions this was not possible. What I recommend is to put a pan under the tree and turn the sprinkler on and when the pan has 1 inch of water in it stop.

Fertilizing the tree will also help the vigor use 10-10-10 fertilizer at the rate of 1 lb per inch of trunk diameter, scattered around the tree and watered in good. Do this now and again in the spring.

You did not say where the tree is located but if you are in the U.S. I would recommend that you call the State Forestry Agency and ask one of their Foresters to come take a look. The agencies have on staff a Forest Health section that can ID these pest at the local level. This is a free service. They can look at the growing conditions and also know pest that maybe in high populations for that area and can recommend treatments.