How do you pronounce the Latin genus known as Agastache? In Colorado and New Mexico, where we can grow a wide variety of these wonderful perennials, we generally say the name as A gas tä key, A gas tā key or A gas tä key. I’ve also heard it spoken as A ga stash ē or A gas tash. However, if you’re still not comfortable uttering the name in public, call these superb plants by one of their common names; hummingbird mint or hyssop.
The Blue Ones
In general the blue flowered varieties are the more moisture tolerant of the two color groups. They are also a bit more tolerant of enriched soils. Of the entire genus ‘Blue Fortune’ and the Mid-Western species Agastache foeniculatum (Anise Hyssop) are the most reliably cold hardy. This group of Agastache, are best for feeding butterflies and bees with their abundant nectar .
The Orange, Pinks and Red Ones
The species and hybrids of Southwestern origin (the large flowered orange, pink and red ones) thrive in the cold, arid climates of the Intermountain West. But they are more sensitive than the Blue Ones, to cold, wet winter soils. So they can be challenging to grow in USDA zone 5 & 6, regions further east where rain and snow amounts are in excess of about 25” or more per year.
Of course we gardeners love to push the boundaries when trying new plants. So to grow these incredible flowers in wet zones 5 and 6, I recommend planting them in a container garden or pot where they will thrive. Then you can treat them as an “annual” or bring them into a greenhouse, cold frame or cold sun room for the winter. They will be fine for 2 to 3 years in a pot. In moister, warmer winter climates such as Washington D.C. (USDA zones 7) , the Southwestern species and hybrids are very happy as long as the soil drainage is excellent. NO CLAY!!
The orange, pink and red Agastache are unsurpassed at attracting hummingbirds. If you have them planted, the hummingbirds will find them!
The Secret to Cultivating Agastache
The important thing to remember about successfully growing the Hummingbirds Mints is “tough love.”
- As a general rule, these plants like to grow in hot, dry conditions once established.
- As for their soil, the “leaner” (less fertile) and more well drained, the better. Stay away from rich loams and heavy clay.
- Fertilize organically with a little quality compost and Yum Yum Mix in the fall. Chemical fertilizers will push these plants too much and weaken their tolerance to cold.
- Leave the stems standing over the winter months to increase cold hardiness. Cut back hard in mid-spring.
- Mulching is only necessary in arid climates. Use crushed gravel, pine needles or crushed nut shells at a depth of 1 to 2 inches.
Agastache will act like annuals when grown in rich, fertile soils with too much water and fertilizer. They’ll grow and flower lushly but are most likely to perish over the winter.
The Best Garden Tested Varieties
Unfortunately, many of the newer Agastache hybrids have had limited testing in outdoor growing conditions. Based on my extensive garden experience with these perennials in the Intermountain West, here are some of my top picks.
Agastache Acapulco® ‘Orange’ – Originally bred in Holland by Keift Seed Co. in the late 1990’s, Acapulco ‘Orange’ is a superior cultivar with excellent cold hardiness and vigor. Long-blooming, clear orange flowers and minty foliage are its best attributes.
Agastache ‘Desert Sostice’ – A 2012 High Country Gardens exclusive introduction that I bred, this tough hybrid is a cross between the two best Southwestern species Agastache cana and A. rupestris. A semi-dwarf grower, it has stunning flower spikes with pink and orange flowers and a strong, pleasing herbal scent.
Astastache ‘Ava’ – My best hybrid introduced through High Country Gardens in 2004. If this cultivar is a good fit for your growing conditions, it will be one of your showiest perennials. Blooming for many months beginning in mid-summer, the bright rose-red flowers and non-fading calyxes are stunning.
Agastache cana ‘Rosita’ – A High Country exclusive. A semi-dwarf form of the species, A. cana that I found some years ago grown from habitat collected seed from southern New Mexico. It has about 50% more bright rose-pink flowers (corollas) in the spike than is typical, so the flower spikes are particularly plump and full. ‘Rosita’ has a most delicious sweet herbal fragrance too.
Text and Photos by David Salman