Question
Hi!  I have a beautiful coral bark japanese maple that we planted in a sunny location location about 3 years ago.  It's been doing well, but this past week we noticed a brown sap oozing from the trunk about a foot above the ground.  Is this a disease or pest, and is there anything we can do about it?  I'd hate for this tree to die because it is so beautiful year-round!

Answer
Sounds like an insect called a borer. The bark of maple trees in thin and any damage to the bark will cause the tree to ooze sap. First make sure that the tree was not damaged say by a weed eater getting to close.(mulching around the tree with not more than 3 inches deep of organic mulch will keep this from happening an help hold moisture around the roots.
Borers will infest wounds and and can be controlled with the use of an insecticide called merit. Spray the area and the Merit will be absorbed by the bark and kill the insect in the tree. Or a newer product called Bayer Advanced Tree and Shrub Insect Control can be used by applying it to the soil around the tree and the roots will translocate the insecticide to the trunk limbs and leaves killing the borers. This product will give linger protection than the spray and is easier to apply. Check with your local nursery for this product. Here is a web link to this Bayer Advanced.
http://www.bayeradvanced.com/product/Tree-Shrub-Insect-Control/concentrate.html