Hydrangeas are shrubs, not perennials, so they can't really be divided, but they can be propagated from cuttings. They root very easily, probably best in spring, especially in your climate, but I've taken them at many times of year and I think have almost always had success. Use this year's growth, and I always cut just below a leaf node and make sure that the bottom leaf node (with leaves removed but not buds, if there are any) is below ground.
