Extensive root systems in landscaping trees can be a problem if they invade sidewalks and neighboring yards. But deep, extensive root systems as seen in a few species of maple can be useful for preventing erosion. Most maple trees have shallow, noninvasive root systems, but species like the vine maple are an exception.
Maple Root Systems
All tree root systems are composed of large, anchoring roots and smaller feeder roots. The feeder roots absorb water and nutrients from the soil and eventually develop into anchoring roots or die to be replaced by new feeder roots. The type of soil and other aspects of the growing environment influence the ultimate shape of the root system. For the most part, maple trees have shallow roots, but rooting habits vary by species and environmental conditions. Maple root systems extend laterally and can be invasive, but they usually do not reach deeply into the soil unless conditions are dry. This flat root system lacks a deep taproot. It is shared by maples such as sugar and silver, as well as firs and spruces.
A handful of maple trees are moderately deep-rooted compared with other maple species. The vine maple (Acer circinatum), a small tree or large shrub, is one of these. It grows 10 to 30 feet high but can be slow to establish in sunny locations. The tree thrives with plenty of moisture and prefers part- or full-shade conditions. The extensive root system of the vine maple makes it ideal for stabilizing soil at risk of erosion. Foresters plant the vine maple to help restore wildlife habitats. Arid site conditions sometimes cause shallow-rooted maples to develop deeper root systems as a way to reach moisture available deeper in the soil. For example, the red maple (Acer rubrum L.) produces a short taproot on wet sites, but in dry conditions the taproot will lengthen.
Extensive Root Systems in Maples
Species such as the big leaf maple tree (Acer macrophyllum) have roots that are shallow but widespread and can be massive and anchoring. Allow plenty of space for this fast-growing tree's root system to keep it away from septic systems or water lines. Because the big leaf maple's root system is particularly expansive on sloped sites, it is a valuable tree to use for erosion control. It is one of the largest species of maple, with limbs reaching skyward to 100 feet and creating a 60-foot-wide spread. Leaves, which turn yellow in the fall, can span 15 inches.
Surface roots of maples can create uneven sidewalks and driveways and can be a hazard when they hide in the landscape. As the tree grows, its horizontal roots grow as well -- sometimes causing them to break through the soil surface. If you're concerned about maple roots reaching aboveground, avoid the faster-growing species, such as silver maple (Acer saccharinum) and Norway maple (Acer platanoides).