Why Mulberry Roots Cause Foundation Problems — And What to Do About It

Mulberry trees -- which includes fig, breadfruit, and rubber trees -- are known for their ability to sustain growth in a variety of climates and soil conditions. This is primarily due to their healthy root growth characteristics, even when the branches and fruits aboveground become sparse or debilitated. Mulberry trees do present the homeowner with a potential for foundation problems.

The mulberry tree (genus ​Morus​) consists of at least 12 species, of which three species are generally cultivated for their fruit. Historically, the Morus tree genus has proven useful in a variety of ways. Mulberry leaves are used to feed silkworms and cattle, the bark is used to make paper, and the fruit of mulberry trees is used as a food supplement for domestic chickens and hogs. Owners of orchards even plant mulberry trees as a decoy to keep birds from feeding on their fruit trees, because the birds prefer the fruit of the mulberry trees.

A notable characteristic of deciduous trees -- which includes oak, elm, cottonwood, maple, and mulberry trees -- is vigorous root growth. Mulberry trees in particular are cultivated for their dense branch and leaf growth, which makes them ideal shade and windbreak trees. This density of aboveground growth is supported by equally dense root systems that tend to dominate surrounding soil areas. Mulberry trees that are growing around your home can affect your foundation with their roots.

Mulberry trees can cause foundation problems, but it is not specifically due to the roots penetrating foundation materials. Root growth becomes a problem when the roots affect the strength of the soil beneath the foundation. The soil-bearing capacity under your foundation is critical for supporting the weight of your home. Root growth causes foundation problems when it weakens the soil and causes it to subside. Soil subsidence results in buckling and warping under and around the foundation, particularly in slab-on-grade foundations. Additionally, any foundation cracks that are present will be worsened by the root growth of any tree nearby, especially mulberry trees.

Mulberry trees, like all trees, need water to survive. This is one of the primary responsibilities of root systems, to begin with, and excessive groundwater around your foundation attracts root growth. Leaks in sprinkler systems and plumbing lines, as well as leaking rain gutters and too-short downspouts, cause water to collect in the soil around your foundation. Improper grade levels also cause water to collect.

Resolving these issues will help to discourage root growth and reduce the possibility of foundation damages. More extreme measures -- such as removing the roots of mulberry trees from around the foundation -- may be required, but you should rely on the advice and expertise of a qualified, licensed tree removal company for such a remedy.