Photo by Melody

PlantFiles: Hardy Ageratum, Blue Mistflower
Conoclinium coelestinum

Family: Asteraceae (ass-ter-AY-see-ee) (Info)
Genus: Conoclinium (koh-no-KLY-nee-um) (Info)
Species: coelestinum (koh-el-ES-tee-num) (Info)

Synonym:Eupatorium coelestinum

10 vendors have this plant for sale.

28 members have or want this plant for trade.

View this plant in a garden


18-24 in. (45-60 cm)

18-24 in. (45-60 cm)

USDA Zone 5a: to -28.8 C (-20 F)
USDA Zone 5b: to -26.1 C (-15 F)
USDA Zone 6a: to -23.3 C (-10 F)
USDA Zone 6b: to -20.5 C (-5 F)
USDA Zone 7a: to -17.7 C (0 F)
USDA Zone 7b: to -14.9 C (5 F)
USDA Zone 8a: to -12.2 C (10 F)
USDA Zone 8b: to -9.4 C (15 F)
USDA Zone 9a: to -6.6 C (20 F)
USDA Zone 9b: to -3.8 C (25 F)

Sun Exposure:
Sun to Partial Shade


Bloom Color:

Bloom Time:
Late Summer/Early Fall


Other details:
Average Water Needs; Water regularly; do not overwater
May be a noxious weed or invasive

Soil pH requirements:
5.6 to 6.0 (acidic)
6.1 to 6.5 (mildly acidic)
6.6 to 7.5 (neutral)

Patent Information:

Propagation Methods:
By dividing the rootball
From herbaceous stem cuttings
From softwood cuttings
From seed; direct sow outdoors in fall
From seed; winter sow in vented containers, coldframe or unheated greenhouse
From seed; stratify if sowing indoors
From seed; sow indoors before last frost
From seed; direct sow after last frost
By simple layering
By serpentine layering
By stooling or mound layering

Seed Collecting:
Unknown - Tell us

Click thumbnail
to view:

By Joy
Thumbnail #1 of Conoclinium coelestinum by Joy

By plantdude
Thumbnail #2 of Conoclinium coelestinum by plantdude

By Wandasflowers
Thumbnail #3 of Conoclinium coelestinum by Wandasflowers

By Jeff_Beck
Thumbnail #4 of Conoclinium coelestinum by Jeff_Beck

By Jeff_Beck
Thumbnail #5 of Conoclinium coelestinum by Jeff_Beck

By Jeff_Beck
Thumbnail #6 of Conoclinium coelestinum by Jeff_Beck

By rcn48
Thumbnail #7 of Conoclinium coelestinum by rcn48

There are a total of 27 photos.
Click here to view them all!


9 positives
2 neutrals
2 negatives

Gardeners' Notes:

Positive flowerman48jtdv On Oct 28, 2014, flowerman48jtdv from Southfield, MI wrote:

This is one of my favorite late summer to late fall hardy plants. I believe I bought a couple of clumps years ago at a garage sale here in Southeast Michigan near Detroit. This plant has come back reliably and it spreads. I relocated it from a border near my deck to a meadow I created in the back of my yard. The soil is very poor there and bone dry at times. This plant grows well and spreads but not rampantly. It's perfect for my meadow and it also tolerates shade! I just wish I could get more of it. I've never seen it at any garden centers. I feel lucky to have it in my garden.

Negative turektaylor On Apr 25, 2010, turektaylor from Elizabeth City, NC (Zone 8a) wrote:

WAYYYY too invasive, i'm still trying to pull all the underground roots !!!

Positive Meredith79 On Oct 12, 2008, Meredith79 from Southeastern, NH (Zone 5b) wrote:

I grew this plant from seed in spring and they are blooming wonderfully right now. I used cold treatment and they germinated well. The resulting plants are in a spot that had full sun with a little shade later in the day - while the sun was high in the sky during early summer. Now that it is fall and the sun is lower they get part shade from nearby trees. I hope these are hardy here and reseed because in my opinion, you need a lot to have a nice show of blooms. If they aren't hardy for me I would grow them again as an annual. I've seen them being described as a moist site plant, but they've performed good enough for me with dryish sandy soil.
They need to be placed towards the front of a border, hopefully with a slightly lower growing and long blooming plant in front of them. Mine are in front of and kind of mixed in with Iris and they look nice together. I like the airy effect they have in the garden.
I doubt they would be invasive in a colder zone like 5 or 6. Plus where they are a native, they technically couldn't be. The only place that considers them to be a noxious weed is Kentucky. Although one man's weed.... is another man's treasure : )

Neutral arthurb3 On Sep 25, 2008, arthurb3 from Raleigh, NC (Zone 7b) wrote:

Blue mistflower ("Conoclinium coelestinum), the are great fillers that require no care but you want to place it in a confined area to keep it under control. It add valuable color to the Fall garden!

Positive MotherNature4 On Sep 11, 2008, MotherNature4 from Bartow, FL (Zone 9a) wrote:

These beautiful wildflowers are common in wet hammocks and pond margins throughout the state of Florida.

Positive quiltjean On Jul 26, 2008, quiltjean from North Chelmsford, MA (Zone 6b) wrote:

I got a bit of this from a friend because I love the color in late summer. I put it in a dappled-shade location and it has taken off. To prevent its smothering my precious primula I'm taking out a hunk to plant on our condo grounds. We have terrible soil--silty acid junk with awful drainage--so we try spreaders in shady areas where grass just won't grow.

Positive upsydaisy On Aug 9, 2007, upsydaisy from Rochester, IN wrote:

I got a start of the hardy ageratum several years ago. It does well for me here in north-central Indiana, but I haven't had a problem with it being invasive, possibly because we are in zone 5. I really love it, and so do the butterflies!

Negative sterhill On Mar 31, 2006, sterhill from Atlanta, GA (Zone 7b) wrote:

A friend of mine gave me this last summer and it bloomed big and beautiful. Now I am picking out millions of seedlings... and I find I can't just pluck out a little seedling but I have to dig down at least 4-6 inches as the roots go 'way down and I find a mass of white roots ready to spring up more seedlings. She has more shade and I don't think hers spreads like this. Mine are in full sun and are everywhere now!!!

Positive Breezymeadow On Oct 5, 2005, Breezymeadow from Culpeper, VA (Zone 7a) wrote:

This lovely plant grows wild on my property & throughout this area of Virginia (the Piedmont).

The fluffy little violet flowers are a wonderful accent in the late summer/early fall wildflower landscape, & the stem length makes it a nice addition to indoor bouquets.

Positive jnn On Oct 5, 2005, jnn from Chapel Hill, NC (Zone 7b) wrote:

This is a beautiful fall-blooming plant that attracts butterflies and hummingbirds. It does have a tendancy to spread, but you can keep it in check. It is also easy to dig some up to give to friends or put in other parts of your garden.

Positive rcn48 On Dec 19, 2004, rcn48 from Lexington, VA (Zone 6a) wrote:

Lovely addition to the garden for its late summer/fall flowering. Although it can be invasive in some areas, we have ours planted in a border in non-amended soil and in 4 years it has not invaded its companions. Nice cut flower for fall arrangements.

Positive Terry On Aug 31, 2002, Terry from Murfreesboro, TN (Zone 7a) wrote:

I tend to like this plant because it is very carefree - it grows wild in a nearby cow pasture. However, it can be a thug, so watch that you don't plant it near something that has a delicate constitution. And don't feed or water it too much - thin, dry soil will help keep the growth in check.

Neutral lupinelover On Aug 31, 2002, lupinelover from Grove City, OH (Zone 6a) wrote:

This plant is highly invasive in loose to medium soil. The beautiful flowers in late summer and autumn help to compensate for trait, though. Grows and flowers well in full sun to medium shade, wet to dry. A wonderful addition to a meadow or natural wildflower planting area large enough to accommodate a beautiful wildlife attractor.


This plant has been said to grow in the following regions:

Auburn, Alabama
Morrilton, Arkansas
Elk Grove, California
Fort Lauderdale, Florida
Jacksonville, Florida
Merritt Island, Florida
Miami, Florida
Oldsmar, Florida
Riverview, Florida
Calhoun, Georgia
Decatur, Georgia
Watkinsville, Georgia
Crescent City, Illinois
Itasca, Illinois
Mount Prospect, Illinois
Greenville, Indiana
Rochester, Indiana
Wichita, Kansas
Morehead, Kentucky
Taylorsville, Kentucky
Weeksbury, Kentucky
Abita Springs, Louisiana
New Orleans, Louisiana
Crofton, Maryland
Valley Lee, Maryland
Westminster, Maryland
Cambridge, Massachusetts
North Chelmsford, Massachusetts
Okemos, Michigan
Southfield, Michigan
Waynesboro, Mississippi
Grandview, Missouri
Hudson, New Hampshire
Frenchtown, New Jersey
Mount Laurel, New Jersey
Chapel Hill, North Carolina
Elizabeth City, North Carolina
Franklin, North Carolina
Greensboro, North Carolina
Raleigh, North Carolina
Winston Salem, North Carolina
Cincinnati, Ohio
Cleveland, Ohio
Glouster, Ohio
Grove City, Ohio
Reynoldsburg, Ohio
Bethlehem, Pennsylvania
Lansdowne, Pennsylvania
Newtown Square, Pennsylvania
Whitehall, Pennsylvania
Barrington, Rhode Island
Charleston, South Carolina
Conway, South Carolina
Florence, South Carolina
Saint Matthews, South Carolina
Clarksville, Tennessee
Nashville, Tennessee
Arlington, Texas
Austin, Texas (2 reports)
Carrollton, Texas
Cleburne, Texas
Crowley, Texas
Dripping Springs, Texas
Harlingen, Texas
Helotes, Texas
Irving, Texas
Longview, Texas
Meridian, Texas
Princeton, Texas
Rye, Texas
San Antonio, Texas
Alexandria, Virginia
Arlington, Virginia
Hood, Virginia
Leesburg, Virginia
Lexington, Virginia
Kalama, Washington
Milwaukee, Wisconsin

We recommend Firefox
Overwhelmed? There's a lot to see here. Try starting at our homepage.

[ Home | About | Advertise | Media Kit | Mission | Featured Companies | Submit an Article | Terms of Use | Tour | Rules | Privacy Policy | Contact Us ]

Back to the top

Copyright © 2000-2015 Dave's Garden, an Internet Brands company. All Rights Reserved.

Hope for America