Are Magnolia Tree Root Systems Invasive to Home Foundations?

Function

• Of the nearly 125 different magnolia trees, most develop shallow, wide-spreading roots in the top 1 to 3 feet of soil. Their roots also rarely branch and are much more snakelike and resemble floppy rope. Tree roots are opportunistic -- they grow blindly in all directions to reach fertile soil or a source of moisture.
  
  

Considerations

• Only in rare cases would magnolia tree roots potentially contribute to building foundation problems. Shallow footers may be moved or jarred by a large root, especially if the tree trunk is close by. The Morton Arboretum notes that in seasonal droughts, a magnolia tree's roots may pull away enough moisture to cause the soil under a foundation to subside.
  
  

Size

• Not all magnolia trees mature to the same size. Take tree dimensions into account -- larger trees create larger and more wide-spreading roots. A small star magnolia tree, which looks more like a shrub, would create less foundation concerns than a massive southern magnolia less than 20 feet away from the building.