Anise Hyssop (Agastache foeniculum)

Local Name: Anise Hyssop

Botanical Name: Agastache foeniculum

Family: Lamiaceae

Native Status: Dakota County Native

Landscape Archetype: Prairie and Savanna  

Life Cycle: Short lived perennial

Sun Exposure: Full sun, part sun

Soil Moisture: Mesic to Dry 

Soil Type: Loam, Sand, Clay, Silt

Height & Width Range: Height: Waist (24" - 36") Width: 24”, kind of...this species is highly variable in its width, however usually wider on top than bottom. 

Bloom Color: Purple

Morphology Notes: Flower spikes are terminal, developing at the end of branches with dense clusters of tiny violet to lavender tubular flowers. Blooms began to appear in mid-summer and sometimes persist into fall. Square stems branch out above prairie grasses with opposite, ovate leaves that are softly textured and fragrant when crushed. The leaves often have fine hairs on the underside, a defining feature when compared to its doppelganger Korean Hyssop (Agastache rugosa) which has a hairless underside or only hairs on the veins. This difference results in A. foeniculum presenting as pale and A. rugosa showing a greener leaf underside. The root system is fibrous with short rhizome‑like crowns that don’t penetrate the rhizosphere deeply or spread.

Fruits and Seeds: Nutlets form in late summer to fall, turning brown as they mature, that American Goldfinches (Spinus tristis) delight in all fall and winter. The leaves and flowers are edible to humans with an anise‑minty flavor; commonly used for teas, aromatics, and medicinal applications. 

Habit and habitat: An upright, branching, clumping species common in dry to mesic prairies, open meadows, roadsides, and lightly disturbed grasslands. It performs reliably in poor, sandy, or gravelly soils and tolerates moderate disturbance such as drought, fire, and periodic trimming. In partial shade its form becomes looser and slightly leggy but still flowers. It sometimes spreads by seed but not aggressively like its doppelganger, A. rugosa. Push the limits of where you plant this plant, it will surprise you as a decent performer in drier shade but it is truly at home in the blazing sun. Seed heads are visually striking and subtly ornamental into fall and even winter. They are long lasting flower arrangement components especially when dried. 

Companions: Little Bluestem (Schizachyrium scoparium), Side-oats Grama (Bouteloua curtipendula), Rattlesnake Master (Eryngium yuccifolium), Golden Alexanders (Zizia aurea), Prairie Coreopsis (Coreopsis palmata), Brown-eyed Susan (Rudbeckia triloba), Common Yarrow (Achillea millefolium).

Ecological Associations: Heavily visited by Bumble Bees (Bombus impatiens) and Brown-belted Bumble Bee (Bombus griseocollis), as well as a variety of solitary bees. The tubular flowers also attract butterflies including Black Swallowtail (Papilio polyxenes) and various skipper species, providing a dependable nectar bridge through mid-season gaps when few other prairie plants are in peak bloom. Hummingbirds reliably feed on this plant while other birds and mammals eat the seeds. The most interesting spectacle is watching Crab Spiders (Misumenoides formosipes) and Ambush Bugs (Phymata americana) lurking on the flowers waiting to make a meal of smaller pollinators.  

Provenance: Dakota County, Greater MN

NH Propagation Technique: Seed

Special Powers: Not technically a keystone plant but has received an honorary degree. It feeds insects, birds, and mammals while looking stunning. Use it to make a refreshing tea all year or as an aromatic in baked goods, salads, or cocktails.