Anise hyssop's showy violet flowers attract bees, butterflies and hummingbirds throughout the season.
Anise hyssop is a bushy perennial whose 2-3 in (5-5 cm) leaves really do smell like anise or fennel. The leaves are more or less oval-diamond shaped, toothed on the margins, and velvety whitish beneath. Like most herbaceous members of the mint family, anise hyssop has opposite leaves on stems that are square in cross section. The plants are distinctly erect in habit, usually around three feet (1 m) tall, but can get up to 5 ft (1.5 m) tall. They normally have a spread of only a foot (30 cm) or so across. From summer until frost, anise hyssop produces dense spikes of tiny blue flowers, each set off by a purple bract and calyx. The overall impression is an erect leafy plant with very showy upright violet flower spikes, 2-4 in (5-10 cm) long. Anise hyssop looks quite a bit like some kind of Salvia. (Floridata has profiled several species of Salvia, and Salvia ‘Indigo Spires’ is one example for comparison.)
The cultivar Agastache foeniculum ‘Alabaster’ (aka ‘Alba’) has white flowers. ‘Licorice Blue’ has lavender-blue flowers.
Location Agastache foeniculum is native to the upper Midwest and Great Plains of North America, where it grows in prairies, dry grasslands, open woods, fields, roadsides and fence rows.
Culture Light: Grow anise hyssop in full sun. It tolerates partial shade but gets leggy and produces fewer flowers. Moisture: Anise hyssop does best in neutral to slightly alkaline soils that are moist but well drained. Water before the soil dries out completely. Well established plants are quite drought tolerant. Hardiness: USDA Zones 6 - 10. Propagation: Sow seeds in spring. Seeds do not need to be covered. Stem cuttings are easy to root. Anise hyssop often reseeds itself and blooms in its first year from seed. Although technically a perennial, anise hyssop is often treated as an annual.
Jack grows anise hyssop in containers where it thrives on a hot sunny balcony.
Anise hyssop is a stand up flower. A few three foot (1 m) tall blooming hyssops are a bold presence in borders and perennial flower beds. Use anise hyssop in wildflower gardens, butterfly gardens, cutting gardens and herb gardens. Hummingbirds and butterflies love the flowers. The flower spikes are used as fresh cut flowers and are easily dried for use in dried floral arrangements. Fresh leaves can be added to salads. Dried leaves can be added to potpourris, and are used as a culinary herbal seasoning and for making tea. The seeds can be added to muffins and cookies. The honey made from anise hyssop is said to be light and fragrant. Native Americans used anise hyssop medicinally for a variety of ailments. Apparently deer do not eat anise hyssop.
There are around 20 species of Agastache, most from Mexico and the southwestern U.S., with a couple species in Asia. A half dozen or so are cultivated as garden ornamentals. Don’t confuse anise hyssop and other members of the Agastache genus with the true hyssop (Hyssopus officinalis) of the Mediterranean region. The later is an important medicinal herb that has been used for thousands of years by the Greeks, Romans and many who followed.