When choosing trees for your landscape, it’s essential to consider not only their above-ground beauty but also the impact of their root systems underground. A tree’s roots can extend far beyond its canopy, sometimes spreading two to three times the radius of the tree's dripline.

Selecting trees with appropriate root structures for your environment can provide numerous benefits—such as ample shade, striking fall colors, and wildlife habitats—without the drawbacks of invasive roots.

However, not all trees are well-suited for every yard. Some trees require more space for their roots to spread out, making them less ideal for residential areas. Let’s explore some trees known for their invasive roots and how to manage them, as well as recommendations for trees with less aggressive root systems.

Trees with Invasive Root Systems

Certain trees are notorious for their invasive root structures, which can damage home foundations, sewer lines, and other structures. Here are some examples:

• Willows: Growing up to 40 feet tall with a spread of 35 feet, willows are infamous for their aggressive roots that seek out water, often invading water mains, wells, and home foundations. They thrive near ponds in USDA zones 6 to 8, where they can access plenty of water.
• Norway Maple: This tree, reaching heights of 40 to 50 feet with a dense, rounded crown, is known for its ability to damage sidewalks, driveways, and foundations. To avoid these issues, plant Norway maples at least 100 feet away from your home.
• River Birch: Recognizable by its peeling, two-toned bark, the river birch enjoys growing near water sources in USDA zones 4 to 9. While its roots aren't harmful to foundations, they stay close to the surface, making it difficult to grow other plants nearby. These trees should be planted at least 20 feet from any structures.
• American Elms: The American elm, with its broad, vase-shaped crown, adds beauty to landscapes in USDA zones 3 to 9. Unfortunately, this tree is prone to invasive roots that often find their way into sewer lines and drain pipes.

Trees with Non-Invasive Roots

When designing your garden, it’s crucial to select trees with non-invasive roots, especially near your home or other structures. Here are some trees with roots that are less likely to cause problems:

• Arborvitae: This versatile evergreen grows in a narrow, pyramidal shape, providing privacy and acting as a windbreak. It maintains its green foliage year-round and thrives in USDA zones 3 to 7.
• American Holly: Known for its green leaves and red, berry-like fruits, American holly can reach heights of 40 to 50 feet with a spread of up to 40 feet. This evergreen is a great choice for USDA zones 5 to 9.
• Stewartia: A popular ornamental tree, the stewartia grows to about 40 feet and offers beautiful summer blooms resembling camellias. In the fall, its leaves turn shades of red, gold, and purple. It thrives in USDA zones 5 to 8.
• Crabapples: Compact and versatile, crabapples bloom in vivid magenta each May. They provide year-round interest with their foliage and winter fruits, making them ideal for smaller spaces in USDA zones 3 to 8.
• Hornbeam: The American hornbeam is a low-maintenance tree that adapts well to various conditions, including poor soils. It grows up to 30 feet tall with a 25-foot spread and showcases beautiful fall colors. It’s suitable for USDA zones 3 to 9.

When Should You Consider Tree Root Pruning?

Tree roots are naturally meant to extend into the soil, but sometimes they can grow in a way that chokes the tree, known as girdling. Girdling occurs when roots encircle the tree, cutting off the flow of nutrients and water. This can happen when a tree is planted in a hole that’s too small or too deep.

Correcting girdling roots can be challenging. It’s best to consult a certified arborist to carefully prune these roots without compromising the tree’s stability. Root pruning is also necessary when roots grow in unwanted areas or interfere with other plants. Always avoid pruning roots near the trunk, as these are critical for the tree's structure. The ideal time for root pruning is during winter or early spring.

Final Thoughts

Selecting the right tree for the right place is essential for maintaining a healthy landscape. Understanding the nature of tree roots and choosing trees with appropriate root systems can help you avoid future complications and ensure your trees thrive for years to come.