A tree’s root collar, also known as a root crown or neck, is simply the top of a root system, where the trunk meets the roots. For most species of tree, the root collar is supposed to be partially exposed, sitting just at ground level. The tissues of trees’ roots and trunks have vastly different methods for transporting water and nutrients, so their meeting point at the root crown is critically important to facilitating this exchange.
Why Do Root Collars Need to Be Exposed?
The most important reason for excavating and partially exposing the tree root crown is that trees “breathe” through them, relying on them for oxygen. In addition, the temperature of the root crown is known to be closely correlated with the plant’s overall health and growth. When root collars are buried too deeply, they become vulnerable to the issues described in the next section.
When Does a Tree Need Root Collar Excavation?
There are three common motivations for root collar excavation: to cut back girdling roots, to release excess moisture, and to ease differential pressure.
Girdling roots are those that have grown in so tightly against the root collar that they begin to strangle the tree. This is a common tree root disorder found in trees that were grown in containers with nowhere for their roots to go, or planted to closely to walkways and driveways. Girdling root is also commonly developed in trees that have been planted, or buried, too deeply; the excess soil can encourage the tree roots to expand upward, rather than down.
Excess moisture can build up around trees buried too deeply; if the roots are too deep, water may not seep down to them efficiently enough, and this creates an ideal environment for tree diseases such as fungi and bacteria to grow and attack the tree.
Trees buried too deeply can also experience problems with differential pressure. Like a person buried in sand up to their chin, a tree buried too deeply might have trouble breathing if there’s too much pressure against the organs, or tree roots, it relies on for oxygen and nutrients.
Tree Medics is the Tampa area’s premier tree care service. While most arborists specialize in tree removal, we emphasize tree care, saving trees from pests and disorders before they must be removed. Proper root aeration and fertilization can prevent many tree issues before they begin, and we’ve been treating these cases in the Tampa area since 2004. Call at 813-407-9974 today to schedule a, no-obligation tree service consultation. We Look forward to speaking with you!