A couple years ago I bought a Wood's Blue Aster. It bloomed like crazy the first year and was really stunning. However, last year it spread like mad but didn't bloom nearly as well. This year I notice more spread as little shoots come up on the edges but not much seems to be happening in the center of the plant. I know it's still early, but will dividing it rejunvenate it? If I divide it, do I just cut it in half or take the little shoots along the edges and discard the woody center? I know that's what's recommended when dividing mums. Thanks for the advice.