Juniper Tree Roots a Potential Problem?

Q: There is a retaining wall (professionally built, 1 ft. wide concrete slab) about 4.5 ft high in my property, I recently planted a Wichita Blue Juniper on top of the retaining wall and close to the edge of the wall. I didn’t think about the issues of the roots and the retaining wall at the time when I planted the upright Juniper, now I am concerned whether the roots of the juniper will eventually damage the retaining wall? Would you recommend that I should move the juniper to prevent any potential damage to the retaining wall?

Junipers are well adapted to dry soil conditions. They usually have a very deep taproot to take up water from deep in the soil, as well as a mat of fibrous roots closer to the soil’s surface to capture rain water. Juniperus scopulorum ‘Wichita Blue’ is an upright grower to about 15 feet, which is really a tall shrub rather than a tree. Therefore, unlike the extensive root system that would be required to anchor a very tall tree, I doubt your juniper will develop roots that would damage your retaining wall. At one foot thick it sounds very sturdy!