Hoary Vervain is a rugged and beautiful perennial that is a staple of the American prairie, known for its silver-green foliage and long-lasting purple blooms. The 'hoary' in its name refers to the dense covering of fine white hairs on its stems and leaves, which give the plant a soft, velvety appearance and help it conserve moisture. It produces tall, pencil-thin spikes of lavender-blue flowers that bloom sequentially from mid-summer into early fall. Growing 1 to 4 feet tall (occasionally reaching 6 feet), it is a common sight in dry prairies, pastures, and fields across the central United States. It is exceptionally drought-tolerant and thrives in full sun and well-drained soil. Hoary Vervain is a favorite of many pollinators, including the endangered Rusty Patched Bumble Bee, and its seeds are a valuable food source for birds. It is also highly resistant to deer and livestock grazing, making it a reliable and persistent choice for restoration projects and home landscapes alike.

Quick facts

• Height: 1–4 ft
• Sun: Full to Partial
• Soil moisture: Medium-Dry to Dry
• Bloom time: Jun–Sep (Blue)
• Life cycle: Perennial
• Native range: Native to 38 states, including Iowa, Minnesota, Wisconsin, Illinois, Missouri, Nebraska

See the full growing guide and county range map for Hoary Vervain