Is Agastache a Hyssop?

About Agastache

• The agastaches, or hummingbird mints, produce profuse stalks of blue, purple, pink or white tubular flowers that bloom continuously from June through September. Hummingbirds and bees adore these plants. Hummingbird mints prefer well-draining or sandy soils and grow in U.S. Department of Agriculture plant hardiness zones 5 through 10. In winter, the plants die back to a basal rosette of leaves.

Non-Native Hyssop

• True hyssop (Hyssopus officinalis) is an herbaceous perennial that has been known since ancient times, and the Greek root of its name, “hussopos” or “holy herb” points to its long traditional use. Though this plant and hummingbird mint both belong to the mint family, they are otherwise unrelated. One key difference is in the leaves: hummingbird mint has triangular leaves with toothed margins while the leaves of true hyssop are bladelike. Like hummingbird mint, bees favor hyssop and it was was historically important in the production of honey. Today, true hyssop is a good choice for Mediterranean-style gardens, as it thrives especially well in warmer climates with well-drained to sandy soils. It grows in USDA zones 4 through 9, and from zone 6 and warmer, hyssop can be used as a semi-evergreen shrub that reaches up to 2 feet in height.

Growing Hummingbird Mint

• Hummingbird mints have gained a committed following because of their extreme toughness and wide selection of forms. They are xeriscape favorites, preferring well-drained soils of low fertility. Because of the similar growing requirements, they work well as companions to plants like lavenders (Lavandula spp.), which grow in USDA zones 4 through 9, and catmints (Nepeta spp.), which grow in USDA zones 3 through 8. Despite their preference for austere living quarters, hummingbird mints are a star performer with generous stalks of flowers ranging in size from several inches to more than 4 feet tall, depending on the variety. Foliage color can also differ widely.

Hummingbird Mint Varieties

• Popular varieties of hummingbird mint include the standard species, called anise or giant hyssop (Agastache foeniculum), for the licoricelike scent of its lavender-blue flowers and 4-foot height. “Blue Fortune” is a cultivar with powder-blue flowers over dark green foliage, while “Golden Jubilee” is a selection with bright, chartreuse-yellow foliage. “Heatwave” has hot-pink flowers and is exceptionally tolerant of heat and humidity. For smaller gardens, “Purple Pygmy” is shorter, growing only to about 16 inches, with dark pink or purple flowers.