Question
My red tip maple is 8 years old and and a large limb at the crotch has fallen and torn the bark from the main trunk down to the
ground. A large black spot about the size of a softball was found
where the limb came from. I have used sealer on the trunk and the tree has continued to bloom. The tree is about 30 feet high and the diameter of the lost limb is about 12 in. at the base. I don't know what caused the rot inside the tree. Should I keep tree/ Thank you

Answer
In general I would say the tree does not need removing. Decay fungi get into the woody cells of a tree through a wound and over many years will decay the inside of the tree causing it to become hollow. Decay fungi do not infect the living cells in the cambium layer and there fore do not in themselves kill a tree. IF the decay has progressed into the upper wood of the trunk and the limbs normally large limbs can break off. You can tell this by where the limb broke at the trunk the wood is soft or the area is hollow. IF the wood is soft this usually means the decay has advanced into the top part of the tree. These tree with this advanced decay can be classified as hazard tree, depending on their location. IF the tree is near a building and if it fell would damage a building then this would be a hazard tree. In this case you would need to watch and IF more large limbs with soft wood fall you may have to take it down OR if it were to fall on a building. IF you are unsure you might want to call the local office of the State Forestry Agency and have one of their Foresters look at the tree and help decide IF it is indeed a hazard.

I would in any case fertilize the tree with 10-10-10 fertilizer at the rate of 1 lb per inch of trunk diameter scattered around the tree and watered in good. Apply just before a rain storm and you will not need to water. This will increase the overall health of the tree.

Sounds like your tree will be OK it just has decay from its age and with care should live many more years.