Mists of bluish purple flowers appear in early fall and dance across 2' mounds of coarsely-toothed leaves—adding gorgeous color among golden falling leaves. This back-of-the-border-beauty is adapted to most soil types, but is strongly suited for highly organic soils. Hardy Ageratum also shines when used in containers, rock gardens and cut flower arrangements. Growing about 3' tall, this rhizomatous perennial often forms colonies, is deer resistant and attracts butterflies and other friendly pollinators. Plant in full sun to partial shade. Eupatorium coelestinum.