Close observation can help you determine if your tree is dead. For example, if fungus is growing at the base of the tree, your tree may be decaying from the inside out. Other outward signs of a dead tree include vertical cracks on the trunk, damaged roots, and a failure to produce new leaves.
Another easy way to see if the tree is dead is to do a simple scratch test. Scratch a small section of bark to see if there is a green layer underneath. If the tree is green underneath, then the cambium layer—which helps the branches, trunk, and roots grow thicker—is healthy. If you do not see a green layer, that section of the tree may be dead. Check other spots on the tree to make sure that the entire tree is dead before deciding to cut it down.