Trees provide many benefits to our environment and can be among your landscape’s greatest assets. Healthy trees can add as much as 20% to the value of your property. However, when a tree is under stress or in declining health, the problem may lie below ground and out of sight. Two issues that can cause declining health in trees include planting the trees too deep, and improperly applying mulch to the base of the tree. A root collar excavation can help diagnose the issue.