Many people plant their trees too deep, and container grown trees can be prone to stem girdling roots. Click on the link to learn more…
A stem girdling root is a root that grows in a circle around the tree. Over time as the tree's trunk gets larger, the root wraps around the trunk strangling the tissues in the tree that conduct nutrients and water from the roots to the leaves. This leads a tree to die prematurely. Instead of a big beautiful tree that grows for 50+ years, your tree may start to die back after only 10 years. In most cases, stem girdling roots result from planting trees too deep or not correctly prepping a container grown tree before planting. (Learn more about stem girdling roots - http://www.myminnesotawoods.umn.edu/2009/01/stem-girdling-roots-booklet/)