Trees can be planted too deep and the culprit is typically our over-caring urges to protect them. We want to ensure the tree is anchored solidly and is well braced so we think that planting it deeply accomplishes this. But more often than not you’d be wrong. Even professionals can make the mistake; one recent study suggests that 93% of professionally planted trees are planted too deep.
When tree roots are planted too far underground, secondary roots grow toward the surface to compensate. Rather than growing up and then out from the tree, they often encircle the trunk (called “girdling roots”) and ultimately choke it out. It can also cause bark on the trunk to start falling off and make the tree more susceptible to disease and pests.