2 Answers

I have a Maple in front of the house that was damaged by a bear's claws. It has a long split in it but the tree is doing just fine, grows like hell, two feet a year. Leave it alone their a lot more durable than you think.

It sounds like you may have multiple problems with the tree. Borers or carpenter ants could be in it, weakening it and making it susceptible to disease.

The defoliation is probably environmental--like too much or too little water or too much heat. A tree can usualy defoliate one year and the next it will be fine but if it happens more than one year in a row it starts to weaken the root system. When the roots go--it's gone.

Spliting trunk is usually frost or lightening. Like I said it sound like this particular tree is getting pounded and you may start to get used to the idea you may lose it. If it's a junk maple, like a silver maple, sometimes they lose bark and are more likely to get carpenter ants. I'd get rid of a silver maple and plant a "good" maple like red maple or sugar maple or Norway maple. If it is one of the w better maples you may want to call in the Tree Doctor and find out if it has a chance and what it would cost to treat it.