Anise-hyssop is a short-lived perennial with profuse, long-lasting, tight spikes of lavender-blue flowers. The leaves and flowers smell like anise. It is an excellent ornamental for the summer garden.
Anise-hyssop has an erect, upright habit reaching 2 to 3 feet high. It is a short-lived perennial, living two to three years.
Native geographic location and habitat:
This perennial is found in dry rocky areas and open woodlands and prairies from North Dakota to Kansas, west to Colorado and northern Mexico. It attracts hummingbirds, butterflies, bees, and other pollinators.
The leaves are opposite, dark green, 2 to 3 inches long and 1 inch wide, ovate to lanceolate with serrate margins. Leaves are often tinted purple, especially in cooler climates. The underside of the leaf is felt-like. It has a strong smell of anise (licorice), tarragon, or basil.
The flowers are tightly packed on 4 to 5 inch long terminal spikes. Individual flowers are 1/4 inch, tubular, lavender blue with a larger violet bract. The long-lasting flower spikes begin in mid summer and make good cut flowers.
The seeds are a tiny nutlet. The plants can reseed readily.
This plant does best in a full sun, moist, well-drained site. Cut back plants in spring to a height of 12 inches to promote more stem branching and fuller growth. It is drought and heat tolerant once it is established.
List of pests and diseases:
Anise-hyssop does not tolerate wet conditions. Powdery mildew can be a problem as well as two-spotted cucumber beetles (occasional problem).
Hybrids are usually showier and hardier and come in a variety of colors. Most are 2 to 4 feet high with fragrant, gray-green leaves and dense terminal spikes.
Alba anise-hyssop (Hyssop foeniculum ‘Alba’ (syn. ‘Alabaster’):
This cultivar has pale green leaves and creamy white flowers.
Golden Jubilee anise-hyssop (Hyssop foeniculum ‘Golden Jubilee’):
This plant has golden yellow foliage with lavender-blue flowers.
Licorice Blue anise-hyssop (Hyssop foeniculum ‘Licorice Blue’):
A cultivar with green foliage with lavender-blue flowers.
Licorice White anise-hyssop (Hyssop foeniculum ‘Licorice White’):
This plant has medium green foliage with white flowers.
Black Adder hyssop (Agastache ‘Black Adder’):
This 2 to 3 feet high and 1 to 2 feet wide variety has black buds that open to smoky red-violet flowers.
Blue Blazes hyssop (Agastache ‘Blue Blazes’):
A 3 to 4 feet high and 2 to 3 feet wide plant with lavender-pink flowers.
Blue Fortune hyssop (Agastache ‘Blue Fortune’):
Another 3 to 4 feet high plant with lavender-blue flowers.
Heatwave hyssop (Agastache ‘Heatwave’):
A 2 to 3 feet high plant with spikes of magenta-pink flowers and soft green leaves.