How far does the root system of a crepe myrtle tree spread? I have an oleander tree now in the 5' planter between my driveway and my neighbor's. My sewer line is about 4-5' away from the oleander, and there is a problem with roots from the oleander intruding into the sewer line. My HOA says I can remove the oleander and replace it with a crepe myrtle, which supposedly does not have as big a root spread. Is that correct?
Certified GKH Gardening Expert
Yes. Generally, the root system will extend at least as far as the canopy of the tree (if unpruned), but some may have a root system up to three times as wide as the canopy, or drip line of the tree. However, with crepe mytle trees, there's no need to worry much about invasive roots, as their root systems are not aggressive, meaning they are not strong enough to pose any major threat to nearby structures or plants. Nonetheless, while they do not usually have an extensive root system, it is always recommended that they be planted at least 5-10 feet from foundations, walkways, sewer lines, etc.