Agastache nepetoides (Yellow Giant Hyssop)
|Also known as:||Catnip Giant Hyssop|
|Habitat:||part shade, sun; moist open woods, thickets, woodland edges|
|Bloom season:||July - October|
|Plant height:||3 to 5 feet|
|Wetland Indicator Status:||GP: FACU MW: FACU NCNE: FACU|
|MN county distribution (click map to enlarge):|
|National distribution (click map to enlarge):|
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A dense, narrow, 2 to 8 inch spike of pale greenish to yellow flowers at ends of stems and branches, often with several separated flowers at the spike base and only scattered flowers open at any one time. Flowers are tubular, about 1/3 inch long with four irregular lobes: a broad fringed lower lip, two small lateral lobes and smaller fringed upper hood. 4 slender stamens and single style, forked at the tip, extend conspicuously from the floral tube.
Leaves and stems:
Leaves are thin, generally egg-shaped, rounded to nearly heart-shaped at the base, pointed at the tip, with coarsely toothed edges and fine hairs on the lower surface. Lower leaves are up to 6 inches long including a 2 inch stalk, to 3 inches wide; the upper leaves are smaller.
Stems are stout and strongly four-angled, heavily branched throughout, typically smooth but sometimes with minute soft hairs, especially on the the leaf stalk.
Yellow Giant Hyssop is a southern species of open woodlands and thickets. While Minnesota is the northwestern edge of its range, the two documented occurrences are from the Lac Qui Parle river bottoms in Chippewa and Lac Qui Parle counties in west central MN. Presently listed as a “tracked” species by MN-DNR, in all likelihood there are other locations out there pending some botany enthusiast with an open mind and open eyes, spotting it.
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Photos courtesy Peter M. Dziuk taken in a private garden in Ramsey County.
Have you seen this plant in Minnesota, or have any other comments about it?
on: 2014-08-28 20:57:53
Populations of native yellow giant hyssop occur here in the Driftless region. I have pressed specimens and images readily produced. Habitat loss has taken three of the known populations,meeting purple giant hyssop which is infiltrating these once more open situations is perhaps their greatest threat..
on: 2015-06-23 10:00:44
Came up on south side of home, growing in rock.
on: 2015-08-29 14:47:05
I found Yellow Giant Hyssop in Camden State Park and along the Redwood River near my home just north of the City of Lynd.
on: 2015-09-01 13:54:58
It came up in my alley garden, which was already planted to natives. This garden is partly shaded. Yellow giant hyssop is taking over. Bumblebees and honeybees really like it.
on: 2015-09-01 13:56:05
Janet, it can produce copious amounts of seed. Dead-heading helps, and raking can clear out the seedlings. Whoever said native plant gardens don't require any maintenance never had one!
on: 2017-08-02 10:47:10
Have a few of these in my native shade garden...I'm commenting though because it was difficult to identify them on your website. I eventually had to broaden my search to this very vague set of criteria to find it:
Criteria: type=flower; flower=yellow,irregular,spike;
You may want to look into the search setup for this species?
on: 2017-08-02 17:25:21
Angie, without knowing what your original failed search was, it's a bit difficult to figure out what might need adjusting.
on: 2018-08-09 23:24:22
Found a population of this in the Cedar Rock SNA in Redwood county. There were many of them growing right on the granite outcrop in the middle of the SNA. I also found a population in Washington county, near the St. Croix Savanna SNA, along some railroad tracks.
on: 2019-09-09 13:57:06
It just volunteered in our Dakota County oak woods/savanna back yard.
on: 2020-08-19 13:19:30
While doing the Morton Outcrops Self Bio-Blitz on August 18, 2020, I found two large individual plants, both near the end of flowering, immediately adjacent to one of the large rock outcrop "flats" at the SNA. I had not seen this species before...very exciting! A beautiful plant. Not sure if it's been recorded in Renville County before.
on: 2020-09-03 15:14:13
Following up on my previous post...Kari Wallin at DNR SNAs contacted me and verified that this is in fact the first recorded occurrence of A. nepetoides in Renville County!! SNA manager Brad Boldaun may be going out to collect a specimen for the record.