Q.Do you know if columnar oaks have an invasive root system?
We wish to plant a columnar oak, as my husband loves them. The location is about 16 feet from our house. Thank you for any information regarding the root system. Noreen Gibbs
Certified GKH Gardening Expert
They aren't known for it, but all trees have the potential to harm structures if planted close enough.
16 feet should suffice for foundations and structures. Since these trees aren't expansive above ground, you don't need to worry much about branch drop that far out. As long as you aren't planting close to a septic system or sewer lines, it shouldn't be an issue.
Here is an article that will give you more information on caring for the tree: https://www.gardeningknowhow.com/ornamental/trees/oak/columnar-oak-trees.htm
Here is an article that will give you examples of trees to avoid near structures and lines: https://www.gardeningknowhow.com/ornamental/trees/tgen/trees-with-invasive-roots.htm