All the Dirt on Gardening
Scented leaves, gorgeous late-summer flowers and durable plants beloved by butterflies, bees and hummingbirds, make agasataches a garden favorite. Most agastaches are cold hardy to Zone 6, so they will live at least a few years in our climate.
Common names for agastache include: Hummingbird Mint, Anise Hyssop, Giant Hyssop, Sunset Hyssop, Lavender Mint, and Korean Mint.
Agastaches, including A. rupestris, A. foeniculum, and A. aurantiaca, etc., can take the heat as well as an early frost and keep on going. They are drought tolerant so good drainage is important to their survival. They also love sun, even in our humid Zone 7 summertime climate.
Only one or two stems come up on each plant, so a typical butterfly flower bed could hold several plants without crowding. The flower heads can be used in cut flower bouquets if they are harvested while they are no more than two-thirds open.
The scented leaves are 2 or 3 inches long and 1 or 2 inches wide and are hairy on the underside.
Hyssop officinalis, the herb hyssop, Agastache foeniculum or giant blue hyssop, is in the same, mint, plant family but they are distant relations to the garden varieties.
Anise hyssop, Agastache foeniculum, is the native perennial plant that grows up to 3 feet tall with branching stems and 4 inch long leaves.
Anise hyssop leaves smell like licorice and are used for flavoring candy, making tea, and medicinally for treating cold symptoms. More historic medicinal uses are at http://www.alchemy-works.com/agastache_foeniculum.html.
Like all plants with scented, fuzzy, leaves, rabbits and deer leave them alone. The USDA says Agastache clayton ex gronov, giant hyssop, is native across the entire continent (http://plants.usda.gov/core/profile?symbol=AGAST).
Agasatache or hyssop is easy to grow from seed. Seeds that fall on the ground in late-summer will remain dormant until spring. Seeds can be collected now to plant indoors during the winter to provide seedlings to set out in the spring.
The flowers of all varieties feed bees, syrphid flies, skippers, butterflies and moths.
Agastache or hyssop varieties include: alabaster to 3 feet tall with white flowers; honey bee blue, a good selection for flower gardens; honey bee white, an improved alabaster white; and licorice blue and licorice white that will grow 3 or 4 feet tall and are good in a cutting garden.
There is also one creeping variety, Agastache Mexicana that produces many stems and spreads from its root. Rose flowers on 1 foot tall spikes. Cold hardy only to Zone 8.
Last spring, I planted a dozen seedlings along the west side of the vegetable garden fence expecting a continuation of the drought and record heat. With this summer's return to normal rainfall, a few of the seedlings drowned.
Agastache has very few problems though there will be a few insect holes and maybe a bit of mildew or rust if the weather is especially wet or they are planted near an overhead sprinkler.
To grow in containers, be sure the drainage is good and there is plenty of air circulation.
Cold hardiness of the different varieties ranges from Zones 5 or 6 to Zone 10, depending on the one selected.
Sooner Plant Farm (www.soonerplantfarm.com) in Tahlequah offers 20 of the new hybrids, including: Sonoran Sunset, Heatwave, Coronado Red, Mexicana Red Fortune, Kudos Mandarin and Sangria.
Agastache x blue fortune anise hyssop is a Proven Winners selection that many nurseries carry. Oklahoma’s native agastache is agastache nepetoides, or yellow giant hyssop.
Mountain Mint, Texas Hummingbird Mint or Mosquito Hyssop, Agastache cana Bolero, is cold hardy to Zone 5. It has rose-pink flowers on 3 foot tall stems.
Seed sources: Jelitto (Germany) 15 Agastache varieties http://jelitto.com; Swallowtail Gardens www.swallowtailgardenseeds.com, 11-varieties; and, Plant World Seeds www.plant-world-seeds.com has 11 unusual varieties including Green Candles.