How Deep Do the Roots of a Creep Myrtle Grow?

Question

We have some pipes and 200 feet longer near large mature crepe myrtles on a mound in full sun.  The mound is actually an island (median) 20 feet wide. Also on this mound are some woody shrubs (Holly), about 40 years old. Deep beneath the mound (six feet?) are old house laterals (sewers) made of terra cotta pipes. The pipes have become impacted by the roots of the woody shrubs. Can roots of crepe myrtles also go this deep so as to impact pipes? The median is not irrigated and surrounded by pavement, so the only water source is from the leaking house laterals.

Answer 1

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. 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, etc.