Root Barrier – Definition & Detailed Explanation – Arboriculture Glossary

I. What is a Root Barrier?

A root barrier is a physical barrier designed to control the growth of roots in a specific area. It is commonly used in arboriculture to prevent tree roots from encroaching on structures, utilities, sidewalks, and other areas where root growth may cause damage. Root barriers are typically made of materials such as plastic, metal, or concrete and are installed underground to create a barrier that roots cannot penetrate.

II. Why are Root Barriers Used in Arboriculture?

Root barriers are used in arboriculture for several reasons. One of the main reasons is to prevent damage to structures and utilities caused by tree roots. When tree roots grow near buildings, sidewalks, or underground pipes, they can cause cracks, blockages, and other costly problems. Root barriers help to redirect root growth away from these areas, reducing the risk of damage.

Root barriers are also used to protect trees themselves. In urban environments, trees often face limited space to grow and may be planted in areas with compacted soil or poor drainage. This can lead to root girdling, where roots grow in a circular pattern around the base of the tree, eventually strangling it. Root barriers can help to prevent root girdling by directing roots to grow outward instead of in a circular pattern.

III. How Do Root Barriers Work?

Root barriers work by creating a physical barrier that roots cannot penetrate. When roots encounter a root barrier, they are forced to grow in a different direction, away from structures or other sensitive areas. This redirection of root growth helps to prevent damage and maintain the health of trees and surrounding infrastructure.

Root barriers are typically installed underground around the perimeter of a tree or structure. The barrier is placed at a depth that corresponds to the depth of the tree’s roots, usually a few feet below the surface. This ensures that the barrier effectively blocks root growth while allowing the tree to access water and nutrients from the soil.

IV. Types of Root Barriers

There are several types of root barriers available for use in arboriculture. The most common types include:

1. Plastic Root Barriers: Plastic root barriers are made of durable, flexible plastic sheets that are designed to withstand root pressure. They are easy to install and can be cut to fit around trees or structures of any size.

2. Metal Root Barriers: Metal root barriers are typically made of galvanized steel or aluminum and are more rigid than plastic barriers. They are often used in areas where extra strength is needed to withstand root pressure.

3. Concrete Root Barriers: Concrete root barriers are made of precast concrete panels or poured concrete walls. They are the most durable type of root barrier but can be more difficult to install than plastic or metal barriers.

4. Biodegradable Root Barriers: Biodegradable root barriers are made of organic materials such as jute or coconut fiber. These barriers break down over time, allowing roots to grow through them while still providing some level of protection.

V. Installation and Maintenance of Root Barriers

Root barriers should be installed by trained professionals to ensure proper placement and effectiveness. The barrier should be installed at a depth that corresponds to the depth of the tree’s roots and should extend at least a few feet beyond the tree’s canopy to prevent root encroachment.

Once installed, root barriers require minimal maintenance. Periodic inspections should be conducted to check for any signs of root growth or damage to the barrier. If roots are found growing near the barrier, they should be pruned back to prevent them from causing damage.

VI. Benefits of Using Root Barriers in Arboriculture

There are several benefits to using root barriers in arboriculture, including:

1. Damage Prevention: Root barriers help to prevent damage to structures, utilities, and sidewalks caused by tree roots. By redirecting root growth away from these areas, root barriers can help to avoid costly repairs and maintenance.

2. Tree Health: Root barriers can also help to maintain the health of trees by preventing root girdling and promoting outward root growth. This can improve the overall health and longevity of trees in urban environments.

3. Space Management: In urban environments with limited space, root barriers can help to manage the growth of tree roots and prevent overcrowding. This can help to preserve green spaces and prevent conflicts between trees and surrounding infrastructure.

Overall, root barriers are a valuable tool in arboriculture for managing root growth and protecting trees and surrounding infrastructure from damage. By understanding how root barriers work and the benefits they provide, arborists can effectively use them to promote healthy tree growth and maintain urban landscapes.