A guide to help property owners with root spread and its potential damages

Tree root spread is a crucial factor to consider in landscaping and urban development. Roots can extend far beyond the visible canopy, often leading to unintended conflicts with structures, utilities, and other plants.

Understanding how tree roots grow and interact with their environment can help prevent issues like pavement lifting, and structural damage.

In this post, we’ll explore how tree roots spread, factors that influence their growth, and tips for managing root systems in built environments.

1. How Wide Do Tree Roots Spread?

Most people assume that tree roots grow only as wide as the tree’s canopy, but in reality, roots can extend two to three times the tree’s height. For example, a tree that’s 30 feet tall may have roots stretching up to 90 feet away.

Research shows that the extent of root spread can be influenced by factors like soil type, water availability, and the species of the tree.

While each tree species has unique root patterns, most trees tend to grow their roots horizontally rather than vertically, often remaining in the top 18 to 24 inches of soil. This shallow yet wide spread allows roots to access essential nutrients, water, and oxygen more easily.

2. Factors Affecting Root Spread

Tree root spread depends on several environmental factors:

Soil Conditions: Soil compaction and drainage impact root growth. In compacted soils, roots tend to spread horizontally rather than going deeper into the ground. On the other hand, well-aerated soils encourage deeper root growth, reducing the spread at the surface.
Water Availability: Trees in dry climates often extend roots further to access moisture. In contrast, roots in consistently wet soils may not need to spread as widely to find water.
Age and Tree Species: Younger trees tend to spread roots more rapidly as they establish themselves, while older trees may develop more stabilised root systems. Additionally, species like willows, poplars, and silver maples have particularly aggressive roots that can spread extensively and potentially cause issues with infrastructure.

3. Potential Risks of Tree Root Spread

While trees are vital to green spaces, their roots can sometimes pose risks to nearby structures:

Pavement Heaving and Structural Damage: Roots can exert pressure on hard surfaces, causing cracks, lifting, or heaving in pavements, pathways, and foundations. In urban areas, this is often a result of trees planted too close to footpaths or roads without proper barriers .
Utility Interference: Roots can disrupt water pipes, sewer lines, and underground utilities, especially in older infrastructure without modern root barriers. This interference can lead to costly repairs and even compromise essential services.

By understanding these risks, landscapers and urban planners can make more informed choices about where to plant trees and what species are best suited for a specific site.

4. Tips for Managing Tree Root Spread

Proper management practices can help balance tree health with the protection of surrounding infrastructure:

Choosing the Right Tree Species: When planting near buildings, roads, or other hardscape elements, select species with non-invasive root systems. For example, trees like Japanese maples and dogwoods are less likely to spread aggressively and are more suitable for small spaces.
Regular Monitoring and Maintenance: Trimming or pruning roots can help manage growth, but it must be done carefully to avoid destabilising the tree. Consulting with an arborist can ensure that root maintenance is done safely.

5. When Roots Cause Problems: What to Do

If tree roots are already causing issues, it’s essential to approach the solution cautiously.

Severing large roots, for instance, can harm or destabilise the tree, making it more susceptible to disease or storm damage.

Instead, work with a tree consultant or arborist to evaluate the safest options, which may include root pruning, barrier installation, or even relocating smaller trees if necessary.

If you’re concerned about potential tree root damage on your property, don’t hesitate to contact us for an expert evaluation and tailored guidance.

Tree Root and Property Damage