You can spend $100—or considerably more—on a beautiful young tree, carefully drive it home, dig a hole, and unintentionally create a problem before you’ve even put the shovel away. The mistake costs nothing: planting the tree too deeply. Digging the planting hole too deep the most common mistake when planting a tree. However, improper depth is by far the most common planting problem its experts encounter. A tree planted too deeply may not collapse next week, which makes this tree planting mistake particularly deceptive. It can struggle to establish, develop girdling roots, suffer decay, and ultimately live a much shorter life than the healthy tree you thought you were buying.