Question
What is the root system like on these plants?  I planted mine next to a pool and was wondering if there would be a danger of the roots damaging it.

Answer
Hi Jon,
Thanx for your question. Hibiscus syriacus (althea) has a deep tap root and so I don't think there will be much of a problem having the plant near the pool as long as it is not planted right next to the concrete or liner.  This plant can be invasive as it self-seeds readily and can be difficult to control.  If you are able to mow frequently around the plant, this usually solves that problem.  I hope this helps.
Tom