Sunset Hyssop

Agastache rupestris, commonly called sunset hyssop or rocky giant hyssop, is an upright, clumping perennial with narrow, licorice-scented gray-green leaves. Its burnt-orange tubular flowers with purple calyces rise on tall spikes from summer into fall, providing a long season of color and nectar for hummingbirds, bees, and butterflies. North Carolina Extension places this species in dry, well-drained Southwestern gardens and reports USDA zones 5a–8b. ## Landscape use and appearance Use this fine-textured plant in sunny borders, containers, rock gardens, and dry slopes where its airy flower spikes can rise above lower plants. The narrow aromatic foliage offers interest outside the main flowering period, while the open clump fits well in naturalistic and pollinator plantings. Its Southwest mountain origin makes it especially suited to gardens with dry air and sharply drained soil. ## Growing conditions Give it full sun, or light afternoon shade in hot locations, and sandy or rocky soil that drains freely. It is drought tolerant after establishment, but prolonged wet soil, particularly in winter, can cause root rot. Published mature-size ranges differ: North Carolina Extension lists 1.5–3 feet tall and 1–1.5 feet wide, while RHS gives a broader height range up to 1 metre and spread up to 0.5 metre. Actual size varies with site and growing conditions. Flowering is reported from summer through fall, with exact timing affected by climate. ## Maintenance Remove spent flower spikes during the season; deadheading after the first flush can encourage a fall rebloom. Avoid excessive winter moisture and allow good air circulation in humid sites. [North Carolina Extension](https://plants.ces.ncsu.edu/plants/agastache-rupestris/common-name/mexican-hyssop/) and the [RHS plant profile](https://www.rhs.org.uk/plants/108381/agastache-rupestris/details) support the identification, landscape traits, and care guidance.