Hardy Geranium 'Rozanne' (Geranium 'Rozanne'): Award-Winning Perennial with Endless Blue Flowers

'Rozanne' (also marketed as 'Gerwat') is a legendary hardy geranium (cranesbill) that revolutionized the genus with its exceptionally long bloom season (early summer to frost), large violet-blue flowers with white centers, and vigorous, spreading habit. It was named Perennial Plant of the Year in 2008.

Botanical Profile

• Family: Geraniaceae
• Genus: Geranium
• Cultivar: 'Rozanne' (PP12175; syn. 'Gerwat')
• Origin: Hybridized by Donald Waterer, introduced 1990.

Outstanding Traits

Forms a mound 18–24 inches tall, spreading 2–3 feet. Deeply lobed, marbled green leaves turn red in fall. Flowers are 2–2.5 inches, violet-blue with prominent white centers and dark veins. Blooms from June to October (or frost) with minimal deadheading. Heat-tolerant and disease-resistant.

Culture

Full sun to part shade. Average, well-drained soil. Hardy in USDA zones 5–8. Shear back by half in midsummer to rejuvenate foliage and encourage rebloom. Divide every 3–4 years.

Uses

Border front, ground cover, rock garden, container, cottage garden. Combines beautifully with roses, salvias, and ornamental grasses.