Root Depth of Hydrangia?

[TerriSteele]

I have 3 plants that are near my septic field. (about a foot away) Will their roots mess up the septic field? I know lilacs roots move toward septic fields and can really mess them up and I don't want to do that with the hydrangias. Any help would be great!

[luis_pr]

Macrophylla and arborescens hydrangeas have a fibruous root system with no large roots and no tap roots. They should be ok for you as I have not heard or read of anyone having a problem near a septic field. Paniculatas can grow the size of trees so those might concern me. However, I have not noticed how their root strcuture is like so I cannot comment about those. Climbing hydrangeas have an extensive root system but I am not sure how deep their roots grow. The root system of a large climbing hydrangea has to support a large plant so I would not try this variety near a septic field either. Not sure about the oakleaf hydrangeas root system but these are most sensitive to root rot. The only one I have had did not exhibit a large root stem but it was only 3-4 years old.