An extremely long-blooming perennial, ideal for edging, rock gardens or containers. Plants are low and tufted or mounding, with taller stems that bear small lacy button flowers of soft lilac blue or sometimes pale pink. Remove faded blooms and plants will continue to flower for months. Attractive to butterflies. Drought tolerant once established. Powdery mildew can sometimes be a problem during the summer; treat this with a preventative fungicide. Divide clumps in the spring every two to three years, or simply replace them with new ones from time to time.