Myth: Tree roots can grow as deeply as the crown is tall
Reality: Most tree roots grow within 3 feet of the soil surface.
Myth: A tree’s root zone extends only as far as the edge of the canopy.
Reality: Tree roots can extend far beyond the tree’s crown and occupy anywhere from two to ten times the area beneath the canopy.
Myth: In forest settings, roots of adjacent trees are separate from one another.
Reality: Roots of trees in forest stands overlap and commingle, forming a dense mat.
Myth: Tree root systems form a circle around the canopy.
Reality: Root growth is highly opportunistic, creating very asymmetrical forms.
Myth: Roots seek out water and mineral elements
Reality: Only the small, fine, short-lived roots function in this manner.
Myth: Trees have large taproots that anchor them to the ground.
Reality: Few mature trees possess a significant taproot.
Myth: Tree roots grow independently of other soil organisms.
Reality: Roots of forest trees coexist with many types of fungi, bacteria, forming mycorrhizal associations.
Myth: Root growth only occurs during the spring and fall.
Reality: Tree roots grow any time soil temperature is above the range of 32 to 40 degrees F. In irrigated landscapes, the peak period of root growth is mid summer.
Source: Trees and Development
