Your tree looks strong and healthy. But its roots might be crying out for help.
One reason why a tree might eventually fail to thrive is the depth at which it's planted.
Planting a tree too deep into the ground can cause reduced tree growth, color and cold hardiness, as well as leave the tree susceptible to disease.
To learn more about proper planting, check out this article by Davey: http://bit.ly/p36dvR