Plant library · Shrubs
Agastache foeniculum
Anise hyssop is an upright perennial that brings lavender flower spikes and licorice-scented foliage to a sunny planting from midsummer into early fall. Reaching about 3 feet tall and 2 feet wide, it has the scale for the middle or back of a border rather than the front edge. Its flowers draw bees, butterflies, and hummingbirds, making it useful where a pollinator-focused bed needs late-season vertical emphasis.
Place anise hyssop in full sun where its upright stems can rise behind lower perennials without blocking a path or obscuring a bed edge. A drift works well along a wide border, meadow-style planting, or open fence line; keep its 2-foot mature spread clear of tight corners and narrow walkways. It also suits a sunny cutting or pollinator area, especially where the planting needs color and activity after many earlier flowers have finished.
Set plants 18 inches apart, center to center, for a closely knit group. Each plant can reach about 2 feet wide, so neighboring clumps may meet and overlap as they mature; reserve a broader bed than the initial planting grid suggests. In a mixed border, leave a reachable strip from a path or open side so spent flower spikes can be removed without stepping into nearby plants.
Use a full-sun position with well-drained soil, avoiding low pockets that hold water around the crown. Once established, anise hyssop fits lower-water planting areas, but drainage remains important even where the bed receives regular rainfall. A raised edge, gravelly border, or slope can help keep the planting zone from staying saturated.[1][2]
Lavender spikes occupy the planting from midsummer into early fall, so position the clump where it can carry the border through the later summer gap. Removing spent spikes can encourage further flowering and keeps the group visually tidier near paths or seating. Allow room for the plant’s perennial return in USDA Zones 4 through 8 rather than treating its bed space as open for seasonal replacements.[1][2]
Avoid sites with persistently wet or poorly drained soil, where crown and root rot can become a problem. The plant may self-seed and spread by rhizomes in favorable conditions, so give it a bed where occasional seedlings can be noticed and managed. In a formal planting, keep it accessible enough to remove spent spikes and unwanted new plants before the clump loses its intended outline.[1][2]
Editorial content updated 2026-07-20.