Whether you have an existing Rose garden or wish to create one for the first time, choosing perennials that will complement the Roses' color and form is an important consideration. Delphiniums always look great with most Roses. Why? Their strong vertical line is a pleasing contrast to the roundness of both the flowers and form of most Roses, while their many shades of blue are beautiful complements to the yellows, pinks, and reds of the Rose family. Another important function of certain Rose companions is to serve as a "petticoat" for the unlovely base of most rose Rushes. Soft, mounding perennials such as Artemisia, Dianthus, Stachys, and Lavender fill this need beautifully. The final element is "filler": a very open, delicate structure that lightly fills the space between other plants. In the Rose garden, tall Artemisias, Caryopteris, Nepeta, and Columnbine perform that function while being attractive in their own right. Choose easy-care Roses that are hardy enough for your region and that match the colors in the diagram.