# What is critical root zone?

**Critical Root Zone**(CRZ), sometimes also called the

**Root**Protection

**Zone**(RPZ), is defined as a circle on the ground corresponding to the dripline of the tree. Unfortunately the “dripline” of a tree can be irregular and hard to define. This full

**root zone**may extend 2 to 3 times beyond the CRZ.

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**.

Additionally, how do you calculate root protection area? The British Standard 5837, RPA is **calculated** by multiplying the diameter of the tree at breast height in meters by 12, but is capped as an **area** with a radius of 15m.

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.

How can we protect tree roots?

**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**.