Turtlehead is an excellent, sturdy, vertical perennial with rounded stems, medium texture and deep-green, boldly veined leaves on short stalks. Weather-resistant flowers are dark pink or purple, borne in short, dense, terminal spikes. The flowers are tubular 2-lipped blooms, with a sparse yellow beard inside each lower lip.Noteworthy characteristics: Blooms for at least 4 weeks and will continue into late summer with deadheading. Great mid-border plant.Care: Grow in partial shade with moist soil. Will grow in dense shade, or even in full sun if soil is soggy. Tolerates heavy clay soils and will also grow in a bog garden.Propagation: From seed in early spring. Divide in spring. Root soft-tip cuttings in late spring or early summer.Problems: Prone to powdery mildew, rust, fungal leaf spots, and damage from slugs and snails.