ROOT FLARE EXPOSURE

It is very important to keep the root flare of a tree exposed. The root flare/collar is a transition zone between the trunk and the roots.  Keeping this area exposed and clear of mulch and dirt is critical for the long term structural and biological integrity of the tree.  The root collar is part of the tree’s trunk. Unlike roots, the trunk cannot resist constant soil moisture.  When the root collar is buried by soil or mulch, moisture is trapped against the bark which encourages decay.  Water saturation of the bark inhibits the movement of oxygen and carbon dioxide in and out of the phloem (inner bark).  Over a period of years the lack of gas exchange can kill phloem cells and interfere with the downward movement of food to the roots.  This can stunt root growth and lead to decline of the tree.  Loss of the protective barrier through decay also allows insects and disease to be introduced into the tree.