Centaurea Species, Mountain Bluet, Mountain Cornflower, Perennial Cornflower

Centaurea montana

Family: Asteraceae (ass-ter-AY-see-ee) (Info)
Genus: Centaurea (sen-TAR-ee-uh) (Info)
Species: montana (MON-tah-nuh) (Info)
View this plant in a garden



Water Requirements:

Average Water Needs; Water regularly; do not overwater

Requires consistently moist soil; do not let dry out between waterings

Sun Exposure:

Sun to Partial Shade




Foliage Color:



18-24 in. (45-60 cm)


15-18 in. (38-45 cm)

18-24 in. (45-60 cm)


USDA Zone 3a: to -39.9 C (-40 F)

USDA Zone 3b: to -37.2 C (-35 F)

USDA Zone 4a: to -34.4 C (-30 F)

USDA Zone 4b: to -31.6 C (-25 F)

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)

Where to Grow:

Grow outdoors year-round in hardiness zone



Bloom Color:

Dark Blue

Bloom Characteristics:

This plant is attractive to bees, butterflies and/or birds

Bloom Size:

Unknown - Tell us

Bloom Time:

Late Spring/Early Summer

Mid Summer

Late Summer/Early Fall

Mid Fall

Late Fall/Early Winter

Other details:

Unknown - Tell us

Soil pH requirements:

6.1 to 6.5 (mildly acidic)

6.6 to 7.5 (neutral)

7.6 to 7.8 (mildly alkaline)

Patent Information:


Propagation Methods:

By dividing the rootball

From seed; direct sow outdoors in fall

Seed Collecting:

Allow seedheads to dry on plants; remove and collect seeds


This plant is said to grow outdoors in the following regions:

Juneau, Alaska

Seward, Alaska

Rogers, Arkansas

Citrus Heights, California

Elk Grove, California

Oakland, California

Sebastopol, California

Kiowa, Colorado

Steamboat Springs, Colorado

New Haven, Connecticut

Stamford, Connecticut

Atlanta, Georgia

Cordele, Georgia

Victor, Idaho

Algonquin, Illinois

Cherry Valley, Illinois

Chicago, Illinois

Godfrey, Illinois

Machesney Park, Illinois

Mount Prospect, Illinois

Fishers, Indiana

Gosport, Indiana

Indianapolis, Indiana(2 reports)

Bloomfield, Iowa

Cedar Rapids, Iowa

Inwood, Iowa

Nichols, Iowa

Oskaloosa, Iowa

Pacific Junction, Iowa

Rosalia, Kansas

Ewing, Kentucky

Hebron, Kentucky

Oakland, Maine

Portland, Maine

Marbury, Maryland

Rockville, Maryland

Westminster, Maryland

Amesbury, Massachusetts

Foxboro, Massachusetts

Jamaica Plain, Massachusetts

Norton, Massachusetts

Saugus, Massachusetts

Bellaire, Michigan

Constantine, Michigan

Grand Blanc, Michigan

Grand Haven, Michigan

Mason, Michigan

Novi, Michigan

Pinconning, Michigan

Albertville, Minnesota

Grand Portage, Minnesota

Minneapolis, Minnesota(2 reports)

Rosemount, Minnesota

Florence, Mississippi

Jackson, Missouri

Piedmont, Missouri

Wentzville, Missouri

Willow Springs, Missouri

Big Timber, Montana

Bozeman, Montana

Auburn, New Hampshire

Dover, New Hampshire

Brookside, New Jersey

Binghamton, New York

Brooklyn, New York

Clayton, New York

Deposit, New York

Hilton, New York

Himrod, New York

Lowville, New York

Poughkeepsie, New York

Rochester, New York

Southold, New York

Stamford, New York

Syracuse, New York

Warrensburg, New York

Yonkers, New York

Broadway, North Carolina

Charlotte, North Carolina

Winston Salem, North Carolina

Belfield, North Dakota

Bucyrus, Ohio

Cincinnati, Ohio

Columbus, Ohio

Corning, Ohio

Coshocton, Ohio

Dayton, Ohio

Franklin, Ohio

Geneva, Ohio

Warren, Ohio

Williamsburg, Ohio

Oklahoma City, Oklahoma

Burritts Rapids, Ontario

Albany, Oregon

Baker City, Oregon

Klamath Falls, Oregon

Mill City, Oregon

Millersburg, Oregon

Portland, Oregon(9 reports)

Allentown, Pennsylvania

Coopersburg, Pennsylvania

Johnsonburg, Pennsylvania

Lancaster, Pennsylvania

Lansdowne, Pennsylvania

Lewisburg, Pennsylvania

Mountain Top, Pennsylvania

Pittsburgh, Pennsylvania

Port Matilda, Pennsylvania

West Chester, Pennsylvania

Wynnewood, Pennsylvania

Johnston, Rhode Island

Greenville, South Carolina

Celina, Tennessee

Crossville, Tennessee

Elizabethton, Tennessee

Knoxville, Tennessee

Murfreesboro, Tennessee

Fort Worth, Texas

Jacksonville, Texas

Salem, Utah

Leesburg, Virginia

Mc Lean, Virginia

Springfield, Virginia

Bellevue, Washington

Bremerton, Washington

CHIMACUM, Washington

Cathan, Washington

Everett, Washington

Freeland, Washington

Issaquah, Washington

John Sam Lake, Washington

Kalama, Washington

Lakewood, Washington

MOXEE, Washington

North Marysville, Washington

Olympia, Washington

Port Townsend, Washington(2 reports)

Poulsbo, Washington

Priest Point, Washington

Seattle, Washington(2 reports)

Shaker Church, Washington

Silverdale, Washington

Spokane, Washington(2 reports)

Stanwood, Washington

Stimson Crossing, Washington

Weallup Lake, Washington

Shepherdstown, West Virginia

Fond Du Lac, Wisconsin

Franklin, Wisconsin

Menasha, Wisconsin

Pickerel, Wisconsin

Waukesha, Wisconsin

Cody, Wyoming

show all

Gardeners' Notes:


On Jun 9, 2016, LindaRmfg from Willow Springs, MO wrote:

I love this flower. The color is lovely and it looks beautiful with irises and sweet william in the spring. It does reseed itself, creating a wash of blue across the flower bed. Also, the bumblebees adore it, so it's a good source of food for them in the spring when the queens are foraging. I can only say good things about mountain bluett.


On Feb 17, 2016, rosemary10 from Walnut Creek, CA wrote:

We had this in our garden when we lived in Seattle years ago. It was an old garden, with only the plants that had survived a lot of neglect left when we commenced working on the garden. It wasn't particularly hard to keep in control there.

I loved this flower for its intense blue and for its lovely peach fragrance. But my husband could not detect any fragrance at all. We canvassed our friends - some noted a strong peach fragrance, some could detect no scent, and one could detect only a very light fragrance.


On May 11, 2015, coriaceous from ROSLINDALE, MA wrote:

The flowers are beautiful, taken individually, and in a rare shade of true blue. And flowering continues for a long season. But even at peak bloom, there were never quite enough of them to read well from a distance in the garden. And it isn't worth growing for the foliage alone. So, after some years, I got rid of mine.

I found it fairly aggressive, but I could have dealt with that if it were more generous with its bloom.

According to BONAP, this species has naturalized in 14 states and 6 provinces, but it is nowhere invasive of natural habitat.


On Dec 25, 2014, pmmGarak from Gppingen,
Germany (Zone 7b) wrote:

Some call it invasive, i call it brilliant to fill unused spaces, especially since the seedlings are easy to tell apart with those hairy leaves. In mild winters such as this (here in Germany), they may flower in the middle of December!
I'm even lucky to have a purple flowering mutant - or maybe it's a hybrid with one of the wild Centaureas? Everything but the color looks as usual.
Careful at dry places: may catch some mildew.


On Sep 10, 2014, cnggreen from Rosalia, KS wrote:

I've had this plant previously in my garden but due to a lengthy, multi-year drought it died out. I recently acquired another one and will try to re-establish it once again. I thought it was lovely, and not at all weedy looking. I didn't have the problem of it becoming invasive because we tend to have a lot of long dry spells. I cut mine back after the first flush of flowers and then it will re-flower again in September.


On Jul 26, 2014, quasymoto from Bloomfield, IA (Zone 5b) wrote:

I love it, I have wanted this for some time, but finally got it this year. One thing. Mine blooms WHITE, it's not blue. But from the photos it's the same plant.. It has had babies this summer, side shoots that popped out. In the fall I plan on digging them up and adding them to other area's.


On Apr 22, 2014, kmm44 from Dayton, OH wrote:

My son gave me some mountain bluet years ago and it is one of my all-time favorites. I read the comments above and it amazes me that anyone could call the foliage weedy. Invasiveness is in the eye of the beholder. Yes, it spreads, but not out of control, at least in my yard. I always look for extra plants to pot up for my garden club's plant sale the 3rd week in May.
The flowers are gorgeous! They fit right in with my tulips and other spring bloomers. When they finish blooming and start to look ratty, I cut them back to the ground and they sprout again with a later bloom, not as prolific as the first, but a welcome mid-summer addition. I have never had trouble with slugs or any other kinds of pests.
All in all, it is a wonderful plant.


On Oct 11, 2013, mehitabel45 from Whidbey Island, WA (Zone 8b) wrote:

I was warned about this plant, that it was invasive. Well, I've had worse, and not with such insanely great flowers as compensation. It really is amazing in a vase with tulips and irises. Throw its own foliage away.
Sadly, slugs love the leaves, but they usually leave the flowers alone.
I love this plant, and cut it to the ground as soon as it's done blooming. If I don't, it gets mildew, and looks terrible. I have gotten a second bloom from them, if I'm early enough.
I also find that it needs lean soil to get it to stand up straight.


On Sep 28, 2013, Gredal from Sudbury,
Canada wrote:

I inherited a patch of Centaurea about 6 years ago and our winters are brutal (-40 C/F with windchill) is not uncommon. I have noticed something highly unusual about this flower...I do not deadhead my blooms but let them remain...about 2 months after the original bloom (mid August) the dead bloom develops a new blossom resembling a garlic blossom...I have photos of bees feeding on these second phase blossoms (they are nothing like the typical blossom)...has anyone else noted this?...I will post pictures if it is unusual.


On Jun 3, 2013, JennyWren102 from Mason, MI (Zone 5b) wrote:

Performs beautifully under difficult conditions when other plants around it are struggling. It likes growing in front of my dryer vent in the blazing sun in the West foundation bed. The vent has spread some seed, but seedlings are easy to control when young. Makes a great cut flower for bouquets of wildflowers from the gardens. Next time you cut or deadhead smell the blooms--they're heavenly! Smells like fresh peaches!


On May 26, 2013, hermero from Portland, OR (Zone 8b) wrote:

Like others, this plant was in my yard when we moved to this house in the 90s. The house is 100+ years old, so who knows when it arrived. I don't do anything with it, but let it grow where it wants. It's not invasive really, just moves around the yard some. I have not even collected the seeds as it so freely self sows each year. I thought it was a bachelor button and only recently realized the leaves were not right and the flowers larger. The foliage is quite gray green, pointed oval leaves, and a little fuzzy, so it may not even be mountain bluet, but it is the closest I've seen; abundant deep azure 3-inch flowers. Thank you so much for those who have posted pictures. It really was a big help with this. I am collecting seeds this year to see if I can get it to grow by sprinkling some on ... read more


On Dec 29, 2012, NCDaisy from Lowville, NY wrote:

This plant was here when I moved to this house 8 years ago and I've been trying to ID since then! So happy I stumbled across this site.
My experience has been similar to other posters....the plant is BEAUTIFUL in the spring but once the flowers are gone, the foliage gets ugly and is often covered with powdery mildew. It also tends to spread a bit farther each year. Despite these drawbacks, I've kept the plant because it's such a welcomed site in the spring. After reading other posts, I won't hesitate to cut it back nearly to the ground and am excited to plant some of the other suggested plants around it to hide the spent foliage.
I thought the term 'ruggedly robust' that was suggested by another post was an apt description for this plant :-)


On May 29, 2012, daffodilily from Somerville, AL wrote:

I love bachelor buttons and have seen how well they grow in so many areas! I have been very disappointed with my bedding plants set out about 10 weeks ago. None of the 4 has died, but they have hardly grown. They look limp; watering hasn't helped. They are in partial sun--both shasta daisies and Lenten roses planted in the same area at the same time are thriving. What do I need to do?


On Nov 26, 2010, Vattina from Garrettsville, OH wrote:

If I have the correct plant -- this is a real beauty! I planted a half dead bargain plant and once it took off -wow!
It is just now blooming at the end of November! Can't wait to see what it does next year.


On Aug 9, 2010, madplan from Big Timber, MT wrote:

I have taken my mountain bluet for granted for 30 + years here in zone 4. A friend gave me this plant originally. Every time I moved I brought it along with me. It always performed, sometimes better, sometimes worse. Just this year I decided to identify it and give it the attention it deserves as I notice it is somewhat deer resistant. It's longevity tells me it is certainly hardy.


On Jun 28, 2010, Clary from Lewisburg, PA (Zone 6b) wrote:

Late spring/early summer flowering. Large flower heads make a showy mass of very true blue.

By June the foliage gets yellow and weedy; the plant flops and stretches out everywhere. Where the mound of flowers was is now a pit of yellowing pithy stems. Baby plants are pushing up around the perimeter.

I keep this plant although it not "carefree." The wettest dreariest April weather only makes them grow more, and the garden looks so promising with the fresh woolly leaves sprouting up over the remnants of last year's garden.


On Dec 30, 2009, rmir from Rockville, MD wrote:

I have found this European exotic to be highly invasive in my Central MD garden in full sun. The more I learn about it the more determined I become to eradicate it ASAP. While not unnattractive, its a real thug and I don't want it to spread beyond my yard.


On Jul 13, 2009, bonehead from Cedarhome, WA (Zone 8b) wrote:

As others have noted, this is a true blue flower, stunning in bloom. It does get ratty looking after bloom, but I just cut it back to the ground and the new growth quickly fills in. I have planted this next to Centaurea simplicicaulis which has a pink flower and blooms shortly after montana, and this works well for concealment as well. Blooms May to June for me. Self sows readily, but not a problem to pull the babies (and relocate if you have the space). I've been introducing them to my pasture and woodlot areas where they can have free rein.

Deb, Pacific Northwest


On Jun 19, 2009, GreenThumbBum from Godfrey, IL wrote:

Just happened upon this little jewel at a plant sale! Love the color - finally got the info I needed from this site! I leave some heads on and dead head others for re-bloom - which I am happy to say it has - hoping for 2 re-blooms? I hope this plant follows the other comments and invades away!!! :-)


On May 31, 2009, CATSSTAFF from Westminster, MD (Zone 6b) wrote:

I just love the blue color of this plant!You really can't find a better true blue.

It takes every bit of neglect I can throw it's way and yet still survives. It has horrible heavy clay soil, no suplemental water, no fertilizer, often times this is the area I weed last so it gets competition from weeds and it still does well.

It does reseed itself readily, but I have never found it a problem to move when it comes up somewhere I don't want it to be. I just dig it up and move it elsewhere.

It is great planted amongst my daylilies because as it's done blooming they start and their foliage hides the centaurea foliage.


On May 2, 2007, birder17 from Jackson, MO (Zone 6b) wrote:

I have had this plant for several years but did not know what it was until now. This plant is growing in poor clay soil on the west side at the bottom of my deck steps in full sun. I have nepeta growing by it and a red and pink honeysuckle vine. The color of the perennial cornflower is outstanding. It does reseed in mid summer, but I just pull them up.


On Feb 8, 2007, Bellisgirl from Spokane, WA wrote:

Hi! This plant has very pritty, true-blue flowers. This will be my third year growing it; I am very happy with it. The plant was quite small when I bought it, but it has now formed a nice clump, which I may be able to divide this spring. Mine is in a somewhat droughty area, which may be the reason it has not re-seeded everywhere.


On May 11, 2006, bluegirl77 from Charlotte, NC wrote:

Love it. Planted it 3 days ago & already blooming beautifully. It calls for full sun but I am reading it does well in partial. I recently joined this site to learn more, given my novice gardening skills. My mountain blue is covered in RED ants, which I am now relieved to find is normal.


On Mar 16, 2006, billyporter from Nichols, IA (Zone 5a) wrote:

The blooms are electric blue! It really reseeds, but is easy to control by pulling. It doesn't need watering or any special care. I've had it grow in sun and shade.


On Jan 25, 2006, Gabrielle from (Zone 5a) wrote:

So far this has not been invasive for me. I have moved it several times trying to get it in just the "right spot," so it may not have had a chance. As long as it stays well behaved, I really like it. Another name for it is Perennial Bachelor Button.

Blooms mid May to late July in my garden.


On Sep 6, 2005, Joyous from Himrod, NY (Zone 6a) wrote:

I must agree with haighr, this plant is very invasive in my yard. Thankfully it is in a bed separated from most of my other plants. It spreads with abandon and has roots that seem to go on forever. If I can ever get rid of it I would never bring it back in to my yard again. I do not even offer it as a freebie to my friends.


On Jul 10, 2005, skilledwithands from Issaquah, WA wrote:

This is one of the weediest pretty flowers I have ever seen. I moved into a house that already had these established and I think it is the house I live in that has been the epicenter for this plants spread throughout the neighborhood.
Plants look great while young and in flower... once the flower is done and gone the plant looks rugged and weedy. The plant spreads by offsets produced at the base and very well by seed. They are a pain to uproot.


On Dec 30, 2004, JefeQuicktech from Moorhead, MN (Zone 4a) wrote:

A good hair cut is what this plant needs to keep looking good in MN.

Invasive or just ruggedly robust? We prefer to say the later.


On Dec 28, 2004, Joan from Belfield, ND (Zone 4a) wrote:

This plant has been hardy here in zone 4, and hasn't been invasive for me at all. Actually, I would have given it a positive except that it gets kinda weedy looking in late summer. I'll try cutting it down like someone suggested.


On Jun 28, 2004, dibi from Southampton, PA wrote:

I also loved this plant and tried one. It gave me quite a show of flowers. About June 23 (Holland, PA, zone 6) I noticed something that another subscriber also mentioned. It appeared that the plant was choking and that a cat laid down in the center of the plant and parted it to the left and right. I watered it well but it remained wilted looking. I always deadheaded the plant so I knew it was nothing I purposefully did not do. I decided to cut it down to about an inch in the hopes that the plant will revive itself. I also left the flowers that I deadheaded around the plant, hoping it would reseed itself. I love this plant. It shows beautiful in the sunshine and looks like a sparkler on a birthday cake when it blooms. Any other info on this plant, and also on the yellow variety wo... read more


On Aug 17, 2003, granola50 wrote:

I love this plant so much I moved it from Vancouver BC (Zone7) to Kimberley BC (Zone3) with no problems. I've never had a problem with it getting out of control 'cause as soon as it gets leggy, it is cut right back to the ground and comes back a second time, just like my 'Johnson's Blue' perennial Geraniums. I'm now trying seeds, from a friend who grows Centaurea macrocephala (Yellow Coneflower)with great success in Zone3.


On Aug 1, 2003, vagardener from Springfield, VA wrote:

My garden center identified this plant as a bachelor button. I planted three in a border in full sun and two did very well.


On Jul 30, 2003, myrtle18 wrote:

Very nice. Blooms in spring and still is now (late July). When coming up in the spring, it looks very fresh & lush and comes up fast. After blooming for a while the foliage begins to look gnarly and it is often covered with powdery mildew. You just cut it right back down to the ground and it starts all over again. They bloom in the fall too, even in the snow. Very popular plant in my neighbourhood but not all of them know about cutting it back a few times. I like it so much I have just bought some seeds for the yellow kind, hoping it behaves the same way.



On Jul 30, 2003, MaryE from Baker City, OR (Zone 5b) wrote:

My perennial cornflower (just id'd thanks to the database) was a 4 inch potted plant that I got either free or for 25 cents at a closeout sale. It's planted in partial shade, made a big clump that bloomed and then fell outward like the cat might have layed down right in the middle. I cut off everything that was flat and it came up from the center and it is a nice plant again, blooming for the 2nd time this season, late July now. Mine has ants too.


On Jun 18, 2003, haleygem from Saugus, MA wrote:

I found this plant this year in my new homes garden and love it. The color show is gorgeous and does well in my zone 6 shaded area. Started blooming in early May and is just starting to give up in mid-June. A must have.


On Jun 11, 2003, carolann from Auburn, NH wrote:

Perennial garden staple here in z5. Not invasive in my garden, stays in nice clump with iris blooming around it. The cornflower blue blooms are an excellent complement.


On Aug 1, 2002, haighr from Laurel, DE (Zone 7a) wrote:

I have found these to be the most invasive plants in my gardens. My personal distaste is that the foilage is weedy looking to me. They are not a plant you can just reach down and pull as they root quite deeply. Although the blue flower is attractive, I find the rest of the plant unappealing.


On Jul 28, 2002, darius from So.App.Mtns.,
United States (Zone 5b) wrote:

I started with 2 seedlings from a friend, about 3 years ago. I now have almost a dozen. However, they were in a partial shaded place for 1 year and became quite mouldy and I lost a few. Moving them back to full sun this year has resulted in more blooms and more plants. Self seeding, and require deadheading for more blooms. (Zone 6b, summers seldom above 90 degrees F.)


On Jul 6, 2002, debi_z from Springfield, MA (Zone 6a) wrote:

what a show this multi shades of whispery blue flower puts on in june. with deadheading it will bloom these 2" flowers all summer long. i planted 3, 4" potted plants, 12 inches apart, may 2001. 1 plant prospered that year to bloom, 1 died and 1 hung on for life. spring 2002, with 2 plants now the one hanging on to life grew 2 leaves, then died. The final plant thrived to be ~ 20" tall and 30" wide and has stayed that size now for 2 months. planted at the border of my driveway garden, only 12 inches from the blacktop surface, in full sun it withstands the heat nicely for me. As naturepatch said they must require ants to blossom because they are covered in small black ants. So it is not a plant i cut and bring into the house.
I know this plant as a perennial Bachelor Button.... read more


On May 6, 2002, naturepatch from Morris, IL (Zone 5b) wrote:

Stunning plant when in bloom. Tends to get a bit wilty in high heat, so provide shade. Attracts earthworms. Will self-seed occasionally. Deadheading will prolong bloom time. Might need ants to open like a peony. Ants are always on it when it is getting ready to bloom.