Purple Giant Hyssop (Agastache scrophulariifolia): Tall Native Pollinator Magnet for Moist Sites

Botanical Profile

Family: Lamiaceae (lay-mee-AY-see-ee)
Genus: Agastache (ah-gas-TAH-kee)
Species: scrophulariifolia (skrof-yoo-lar-ee-eye-FOH-lee-uh)
Synonyms: Hyssopus catariifolius, Hyssopus scrophulariifolius, Lophanthus scrophulariifolius, Vleckia cordifolia, Vleckia scrophularifolia

Description

Purple giant hyssop is a stately, clump-forming native perennial reaching 4–6 feet tall. The opposite, ovate, toothed leaves are green and mildly mint-scented. In mid to late summer, it produces dense, cylindrical spikes of small, tubular, lavender-purple flowers that bloom progressively from bottom to top over several weeks. The flowers are highly attractive to bees, butterflies, hummingbirds, and beneficial insects.

Cultivation

Native to moist woods, thickets, and streambanks in eastern North America. Prefers partial shade to full sun with consistently moist, fertile soil. Hardy in zones 3–8. More moisture-tolerant than western Agastache species. Self-seeds moderately; deadhead if spread is unwanted. Divide clumps in spring.

Ecological Value

A premier pollinator plant for moist, partially shaded sites. The long bloom period provides sustained nectar. Seeds feed goldfinches and other birds. Deer resistant. Excellent for rain gardens, woodland edges, and native meadow restorations.