What is critical root zone?
Also question is, how do you find the critical root zone?
Calculating the CRZ The general rule of thumb is that for every inch of tree trunk, the radius increases by 1.5 feet. So once you have the circumference, you just multiply the diameter of the trunk by 1.5, and then you will have the proper radius for your trees critical root zone.
Also asked, what is structural root zone?
The Structural Root Zone (SRZ) is an area around the tree trunk which is essential for tree stability. Damage to the roots in this area will most likely cause the tree to become unstable in the ground, which means the tree can possibly fall over.
Protecting Tree Roots Always use power equipment carefully around the base of trees. Add a layer of mulch. Mulch helps retain moisture, maintain consistent soil temperature and protect roots from damage. Three to four inches is the maximum needed for a mature tree.