A. foeniculum is a herbaceous perennial with mid-green, lance-shaped leaves that taste and smell of licorice. In summer, it bears spikes of lavender-blue flowers that are attractive to butterflies and bees.
The water needs of this plant are low. It requires little watering once it is planted, just enough to moisten the roots. If the soil is damp, do not water.
This plant performs best in full sun but also thrives in part shade. Place it in a location where it receives direct sunlight for a few hours during the day.
Feed it with all-purpose, balanced fertilizer annually during the early spring season. Follow the directions on the package, and make sure to deeply water after fertilizing to avoid root burn.
Trim back Agastache plants by pinching the new growth in spring to promote bushier growth. Deadhead (trim) spent flower stalks to keep the plant tidy. If growing Agastache as a perennial, don't prune or deadhead past midsummer. Pruning too late in the season will stimulate new growth in fall that may not survive the winter.