Pronounced (approximate): ag-ah-STA-kee fen-ICK-yoo-lum
Blue-purple tubular flowers form upright spikes. Square stems support paired leaves and branching flower stalks.
Blue Giant Hyssop (Agastache foeniculum): close view of blue-purple flowers. Tap the photo to open the gallery.
Family Lamiaceae
Life cycle Herbaceous perennial
Blooms Summer–fall
Height 3–5 feet
Habitat Prairies and open sites with well-drained soil
Common names
Blue Giant Hyssop · Anise Hyssop
Bloom timing and height vary with location. Native status refers to North America; see the regional range below.
Explore reported observations. Sightings are not a complete range map.
Prairies and open sites with well-drained soil. Flowering season: summer–fall.
Use leaf undersides and plant structure as well as flower color when comparing giant hyssops.
Blue-purple tubular flowers form upright spikes.
Toothed leaves have pale, softly hairy undersides and an anise-like scent.
Look for herbaceous perennial growth in prairies and open sites with well-drained soil. Pair close views with a photograph of the whole plant.
3 field photographs. Select a photograph to enlarge it.
Native to Canada and the northwestern and north-central United States; cultivated and naturalized farther east.
Reported U.S. native distribution
CO, ID, IL, IA, MN, MT, NE, ND, SD, WA, WI, WY
State records describe documented distribution, not presence in every county. The observation map shows reported sightings and may include cultivated plants.
Observation maps show submitted records, not every place the plant occurs. Follow local access rules when visiting a site.
Practice recognizing Blue Giant Hyssop in the flower quiz, or compare it with other plants in the guide.
Field photographs: Where’s Wildlife.