South Dakota Native Plant Research
Agastache foeniculum

Scientific Name

Agastache foeniculum


Download Seed: The yellowish brown nutlets are 1.3 to 1.5 mm long. (80 KB)

Download Seedling: Three month old seedling of lavender hyssop. (115 KB)

Download Vegetative: The leaf blades are 4-9 cm long and 2-2.5 cm wide. (109 KB)

Download Flowering: The flower spikes can be 4-12 cm long. (57 KB)

Download Fruiting: Lavender hyssop produces fruit in late summer. (87 KB)

Family Name


Common Name

Lavender hyssop, Blue Giant Hyssop

Native American Name

Lakota: wahpe' yata' pi


Agastache foeniculum is a(n) perenial herb rhizomatous, which grows 0.6 m to 1 m in height. This species is commonly found upland woods and prairies(Kindscher). The leaves are opposite, egg-shaped, greenish above, and whitish. Agastache foeniculum has lavender purple bluish purple flowers that bloom from July to August.

Additional Notes: Flowers are five toothed, and appear in whorls, in a simple terminal spikelike arrangement.

Additional Notes

wahpe' yata'pi means leaf that is chewed

Horticulture Notes

Seed Collection: Collect seed in September
Germination: Fall sow or stratification
Vegetative Propagation: Easily planted by division of rootstock cuttings
Soils: Sandy (well drained)
Water: Moist
Notes: The seeds smell like licorice

Agastache foeniculum