|Mat-forming, carefree and generously blooming perennial for summer and early fall. An ideal groundcover, 'Weston' reaches 4 to 6 inches tall and about 12 inches wide. White flowerheads are born on short stems. Silvery-gray, hairy leaves are linear to pinnate. This heat and drought tolerant perennial has a fiberous root system and can become invasive. Divide to maintain. Butterflies are attracted to this plant. Sometimes referred to as Achillea x kolbiana 'Weston'.