Agastache — Hummingbird Mint / Hyssop

Agastache (ah-gah-STAH–key), a member of the mint family (Lamiaceae), is one of the most colorful perennials in the summer and fall garden. Blooming usually lasts until the first hard frost. Plants grow in slowly expanding clumps highlighted by flowers rich in nectar that attracts butterflies, hummingbirds, and bees. Dark to mid-green to greenish gray leaves on thin, stiff, upright stalks are clustered most heavily below colorful spikes of tubular, two-lipped blossoms in white, mauve, lavender, peach, pink, or orange.

Garden Practices

• Of the more than two dozen Agastache species, only a few are usually grown in our gardens.
• Deadheading and removing volunteers helps prevent cross-pollination, although many gardeners rely on self-sowing for prolonged presence since agastache can be short-lived, especially in clay soils.
• Deadheading also encourages repeat, prolonged blossoming.
• Cutting back flower stems and leaves in late winter or early spring encourages dense clumps to develop that may become bushy over time.
• When different species and cultivars are grown together, they may cross-pollinate and their seedlings may not be true to the parent plant.

Agastache Preferences

• Agastacheprefers soils low in fertility but benefits from a light application of compost worked into the soil in fall. Avoid planting in rich or heavy soil.
• Stems that remain standing over winter provide protection from cold spells.
• A hot, sunny spot with excellent drainage is critical.
• Once plants are established, provide only low and infrequent waterings. Drought is more tolerant in coastal sites.
• Considered a habitat plant, agastache attracts hummingbirds more than other wildlife. As birds feed on nectar, they also pollinate flowers.
• Small species may be planted in drifts along the front of borders with larger ones farther back for spectacular statements.
• Intermingle with other sun-loving perennials or plant near the vegetable garden for added late-season color.

Favorite Species and Cultivars

• Agastache foeniculum(anise hyssop or giant blue hyssop) has clumps 3 ft. high spreading 2 ft. wide with anise-scented foliage and purplish blue flowers. A native of north-central North America, this species tolerates Sonoma County winters better than others. Flavored teas may be made from scented leaves.
• Agastache hybrids have been developed in many colors with descriptive names, such as ‘Apricot Sunrise,’ Firebird,’ ‘Tangerine Dreams,’ and ‘Tutti Frutti.’ Hybrids are among the most commonly available agastaches in nurseries.
• Agastache mexicana(giant Mexican lemon hyssop) is one of the taller, common species although it is usually only about 2-3 ft. tall by 1-ft.wide. A long-bloomer from spring through fall, it bears masses of edible deep pink flowers and lemon-scented leaves valued for tea.
• Agastache rugosa(Korean hyssop, Korean hummingbird mint) is another tall grower to 3-5 ft. by 2 ft. wide. Its violet blue flowers bloom the first season after planting. This species tolerates wet feet more easily than most other agastache varieties.
• Agastache rupestris(licorice mint, sunset hyssop) assumes a lower profile than other species, reaching only about 2 ft. high and wide. Spikes of pinkish orange flowers with lilac purple bases and narrow gray-green leaves create a colorful scene for months.

July 2023