Be kind to your roots

The survival of a tree depends upon its root system. The largest of trees to the smallest of seedlings depend on their root systems. One of the most important parts of a tree is its roots — they are responsible for anchorage and support, and absorption of nutrients, water and oxygen from the soil.

Roots also provide a home and host site for beneficial bacteria and fungi, which will assist in the breakdown and assimilation of nutrients. Since the roots mostly lie underground, they are often overlooked despite their importance to the health of the tree.

There are basically two types of roots: the large, woody structural roots that support the tree and keep it firmly anchored in the ground, and the soft, fibrous feeder roots that absorb most of the water and nutrients. Structural roots are generally found around the base of the tree, while the fibrous feeder roots can extend well beyond the drip line of the tree. (The drip line is the outer edge of the tree’s canopy.)

Healthy, rich soil contains bacteria and fungi that grow along with the feeder roots, forming a symbiotic (mutually beneficial) relationship. These organisms produce phosphates and trap atmospheric nitrogen from the air and convert it into a form that can be absorbed by the roots; both are very important macronutrients vital for the growth and health of the tree. In return, the soil bacteria and fungus obtain sugars from the roots, essential for the survival of these organisms.

Roots generally grow in the direction of nutrients and water. The roots need oxygen and a well-drained environment to grow and prosper. Most tree roots live about 15 inches below the surface; however, some trees, such as oaks and hickories, have a deep tap root.

Sometimes barriers in the soil, such as large boulders, clay hardpans, and impervious material, such as concrete, restrict root growth, which may negatively impact tree growth by reducing the water and nutrients it can obtain or by making the tree more prone to topple during a wind storm because it is not anchored well.

Sometimes restricted root growth causes the roots to wrap around one another and girdle the neighboring roots. A tree with girdling roots normally does not have a swell at the base of the tree where it meets the ground, resembling a telephone pole more than a tree. This usually results in large dead branches and trees that are more prone to fall during a storm.

Overwatering trees or planting trees in very wet conditions may limit root growth and cause problems with nutrient uptake and structural stability. Planting trees next to a roadway, sidewalk or other tight space and high traffic areas can negatively affect a tree’s growth, health and lifespan.

Compacted soils and planting tree roots too deep can slowly suffocate the tree, thus leading to its eventual death. Soils are compacted by running machinery back and forth over the roots. Repeated walking around roots can also compact the soil. Tunneling around trees can impact the root system, especially if the large structural roots are cut, making the tree very prone to topple during a storm.

Being kind to their root systems will help maintain the health and beauty of your trees. Whenever you plant a new tree, be sure to look around to see if you are planting the tree in a location that will allow the tree to grow and prosper. Try not to cut large roots during construction projects, and limit disturbances next to trees, and your trees will respond in kind.

Article by FCFCDB

Nature Note for 2/19/2017