Agastache

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Mark McD
Title: Moderator
Joined: 2009-12-14
Agastache

Agastache is a relatively small genus in the Lamiaceae (Mint family); mostly North American except a single species in Asia and Russia (A. rugosa). These are aromatic ornamental herbaceous perennials or subshrubs, the best and showiest ones from southwestern USA and Mexico. They have become one of my favorite genera for a number of reasons; the foliage is light, non-smothering, and aromatic, they bloom all summer long and into fall, flower color runs the gamut from hot southwestern colors (orange, reds, hot pinks) to blues and lavender, and the blooms are highly attractive to hummingbirds. Many colorful multi-color hybrids have been introduced over the past several years.

I start out with the variable Agastache rupestris (threadleaf giant hyssop), from Arizona and New Mexico.
http://plants.usda.gov/java/profile?symbol=AGRU
It makes a shrubby base and a mass of fine stems with silvery linear willow-like leaves, said to smell of licorice or root-beer but more akin to an intense resinous aroma to my sensibility. Starting in midsummer there is an endless profusion of reddish to orange trumpet-shaped flowers, the purplish involucres adding to the overall effect, lasting into autumn. Hummingbirds are highly amused. The plants are perennial but short-lived, lasting 2-4 years, then fading away, but seedlings do show up. Most photos shown here are taken in August and September, a most valuable time for such colorful bloom.

Two views of 2-year shrubs, with very fine filigree of foliage and flowers. The second view also shows a mound of the annual blue-flowered Trichostema dichotomum, with sticky resinous foliage.

Two more photos; the left photo showing a close-up of the blooms on Agastache rupestris, and the right photo is a garden scene showing a nice specimen of A. rupestris on the right, and the brighter orange-flowered Agastache aurantiaca in the lower left. The latter species is from Northern Mexico, although some web sites erroneously report is is also from southwestern USA.

On the left is a photo of A. aurantiaca, less shrubby than A. rupestris, with more open growth, deltoid (triangular shaped) leaves that are irregularly toothed and similarly aromatic to the touch, and open larger-flowered sprays of beautiful medium orange flowers. On the right is another vantage point showing both species, and me (in my heavier weight days) with a strange celestial beam of light shining upon me... I assure you it was just a fluke. ;D

Mark McD
Title: Moderator
Joined: 2009-12-14

Neither Agastache rupestris and A. aurantiaca proved very long lived; after a few years these woody plants tend to die out, replaced by seedlings.  However, all the seedlings that appeared were hybrids between the two species.  Moving forward with this genus, I think it might be wise to take cuttings each year and over-winter them with protection, and set them out again in spring for better insurance that your more colorful forms continue on.  All that I have now are the A. aurantiaca x rupestris hybrids, but I love these too.

On the left, a 2-year old seedling plant of the hybrid, on the right, a close-up view of the soft multi-hued blooms and bracts:

Two photos of the racemes of bloom on sunny days in July and August:

Two close-up photos of the racemes of late bloom, one in September, on overcast days:

While photographing the blooms one late afternoon with dwindling light, I heard a vibrant whir while taking a photo, and I didn't realize until later it was a hummingbird... he's a bit out of focus on the left, but he's there.  I often sit in the garden and simply observe, and the hummers always come around to feed on the Agastache blooms.

Mark McDonough
Massachusetts, USA, near the New Hampshire border USDA Zone 5
antennaria at aol.com
 

RickR
Title: Moderator
Joined: 2009-09-21

I've not grown a lot of agastache, but Agastache rupestris is certainly a winner for me.  My first plant from 2006 seed is still (so far) going strong. Rupestris flowers easily in the first year from seed for me, and I don't detect any off odor from my plants.  It's not surprising there is variation.  The licorice scent is heavenly to me.

Rick Rodich    zone 4a.    Annual precipitation ~24 inches
near Minneapolis, Minnesota, USA

Lori S.
Title: Moderator
Joined: 2009-10-27

Wow, fabulous plants, Mark!  They certainly grow well for you... and I love that "the hummingbirds are highly amused".   :D :D

I can't say I grow Agastache terribly well (other than our native A. foeniculum), so it is encouraging to hear that A. rupestris does well for you, Rick - I must give it a go. 

It was interesting to find that A. pringlei is hardy here.  The seeds were from Alplains, where its hardiness, based presumably on its natural range, is rated very pessimistically as zone 7.  Here is some info on its distribution, which appears to be montane regions in Northern Mexico (Chihuahua) and New Mexico.
http://plants.usda.gov/java/profile?symbol=AGPR3
http://www.joycreek.com/Agastache-pringlei-156-002.htm

Here it is in the garden, just to provide the gist of how it does here... unfortunately not in a rock garden setting (though I hope to rectify that with new seedlings this year):
 

P. S.  Mark, I'm glad you weren't "raptured" away by that beam of light.  ;D

Lori
Calgary, Alberta, Canada - Zone 3
-30 C to +30 C (rarely!); elevation ~1130m; annual precipitation ~40 cm

RickR
Title: Moderator
Joined: 2009-09-21

Lori, that is handsome foliage on that delphinium. 

A. pringlei looks like it might be whispy.  Is it very sturdy, compared to A. foeniculum?

Here is a piece of Agastache rupestris on the right of the photo.  The flower color really isn't exactly true.  It's a kind of burnt orange with pinkish-rose overtones.  Hard to describe but exceedingly pleasing.  I remember taking several pics at different settings, and still couldn't get it right, even later with a photo imaging program. The flowers are definitely not monochromatic.

Rick Rodich    zone 4a.    Annual precipitation ~24 inches
near Minneapolis, Minnesota, USA

Lori S.
Title: Moderator
Joined: 2009-10-27

I actually dug that darned delphinium out last year (though it will probably be back from bits of root that I undoubtedly missed) - it had gotten very big and through vigorous seeding, they pretty much take over after a while!  (Nice plants, of course, but there are dozens of them in the front yard already - don't need them everywhere.)

I wouldn't describe A. pringlei as wispy, exactly, but it is a much shorter and less bulky plant than A. foeniculum, at least as grown in my yard.

A. rupestris looks nice!  What are the unusual seedpods to the left of it - Fibigia?

Lori
Calgary, Alberta, Canada - Zone 3
-30 C to +30 C (rarely!); elevation ~1130m; annual precipitation ~40 cm

RickR
Title: Moderator
Joined: 2009-09-21

Yes, Fibigia clypeata.  Akin to what I would call a weedy stature, although it is not at all invasive.  Very decorative little oval "windows" for dried bouquets,  similar to the big round windows of the Money plant (Lunaria annua).

                     

                                  

Rick Rodich    zone 4a.    Annual precipitation ~24 inches
near Minneapolis, Minnesota, USA

Mark McD
Title: Moderator
Joined: 2009-12-14

Lori, I'm encouraged by the report of hardiness on A. pringlei, a pretty species.  I see that it has toothed deltoid lives similar to A. aurantiaca.  This species is used in some of the hybridization going on with the genus, mostly at High Country Gardens.

Rick, I know what you mean about the difficulty in describing flower color on A. rupestris, a subtle coloration to be sure, the buds are intense, the open flowers softer hued, the prominent calyxes as colorful as the flower but in contrasting color, thus adding to the whole effect.  They look brighter in sun, more muted in shade or low light; I too have not be fully satisfied with any photos I have taken, they fail to capture the true color, which is very pleasing.  A couple years ago Peter George had several plants in flower, they were a darker more muted red color than mine, unfortunately Peter's plants did not survive the winter of 2009/2010  (Peter, any seedlings from those plants?)

From doing some searches, I see that A. rupestris is rated as Zone 4, perhaps one of the hardiest of the southwestern species.

Rick, the Fibigia clypeata is a cool plant, great looking pods; I'm not familiar with it.

Mark McDonough
Massachusetts, USA, near the New Hampshire border USDA Zone 5
antennaria at aol.com
 

Mark McD
Title: Moderator
Joined: 2009-12-14

There are many new Agastache hybrids coming out, many sourced from High Country Gardens.  Do a google search and you'll find many available for purchase.  In the past, I have found that local garden centers are stocking these, I suspect because they flower non-stop in summer and help the sale of perennials.  I grew one called Agastache 'Acupulco Salmon & Pink' for a couple years, with deltoid gray leaves and pink and orange flowers, sadly I should've kept it going with cuttings and lost it after a few years.  It is likely an aurantiaca hybrid.

Agastache at Heronswood, yellow 'Summer Glow', 'Red Fortune' and pink/orange 'Firebird'. The yellow one is a color break for the group, not sure what species or hybrid parentage it came from, but it sure looks nice, although only rated as Zone 6.
http://www.heronswood.com/perennials_perennials-a_agastache/

Agastache aurantiaca, Lamiaceae (Mint family), lots of good close-up photos of several species.
http://www.wildgingerfarm.com/Catalog/Agastache.htm

The Fine Gardening site has a list of species/cultivars.  It starts out with Agastache aurantiaca 'Shades of Orange'. Scroll to the bottom to see more species/cultivars, each has a zone rating key.
http://www.finegardening.com/plantguide/agastache-aurantiaca-shades-oran...

Agastache (lots of 'em) at High Country Gardens, including forms of A. cana with intense burgundy to purple-rose flowers, A. neomexicana (lavender pink).  Most species and cultivars are rated for Zone 5, a couple for Zone 6, and A. rupestris is Zone 4.  Information on hybrid parentage is given for many.
http://search.highcountrygardens.com/?Ntt=agastache&x=0&y=0&view=

A tip from the High Country Gardens site to improve hardiness: Don’t cut it back in the fall; leave the plant standing over the winter to improve cold hardiness.  Interesting, I shall give that a try, as I always cut mine back.  I also suspect microclimate siting is important.  I have watched the woody bases of established A. rupestris and A. aurantiaca show surging fresh shoots early in spring, which get whacked by late frosts, so siting them in spots more protected from frosts, or actually planting them on north facing slopes (yet in sun) where the ground stays frozen much longer, might prevent premature sprouting.

Mark McDonough
Massachusetts, USA, near the New Hampshire border USDA Zone 5
antennaria at aol.com
 

Mark McD
Title: Moderator
Joined: 2009-12-14

Fine Gardening web site article:  "Hooked on Hyssops", good photos.
http://www.finegardening.com/design/articles/hysspos-agastache.aspx

There's a photo of A. aurantiaca ’Just Peachy’... Harold, if you're reading this, you MUST get this one named 'Just Peachy' ;D

Mark McDonough
Massachusetts, USA, near the New Hampshire border USDA Zone 5
antennaria at aol.com
 

RickR
Title: Moderator
Joined: 2009-09-21

I don't cut my Agastache rupestris back until spring, just because that's the way I do it for nearly everything in those gardens - to catch snow since there is no (or little) mulch.  Nice to know I was doing it right!  I don't recall early growth on them, even in my "early" garden.  In fact, I remember some years some sprouts were so late that I wondered if it died that winter.  Perhaps that was because of winter cold damage...

Rick Rodich    zone 4a.    Annual precipitation ~24 inches
near Minneapolis, Minnesota, USA

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