You Should Divide These Perennials in Late Summer
by Amanda Blum from Lifehacker on (#6E7TD)

Perennials-the plants that come back year after year-are always worth the investment. But you can save even more on that investment by simply dividing the plants that are already in your yard: In many cases, you can just calve off some of the existing plant, roots and all, and plonk it down in another part of the yard...