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) |

Category:
Perennials
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:
Herbaceous
Succulent
Foliage Color:
Bronze
Height:
18-24 in. (45-60 cm)
Spacing:
15-18 in. (38-45 cm)
18-24 in. (45-60 cm)
Hardiness:
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
Danger:
N/A
Bloom Color:
Dark Blue
Bloom Characteristics:
This plant is attractive to bees, butterflies and/or birds
Bloom Size:
Bloom Time:
Late Spring/Early Summer
Mid Summer
Late Summer/Early Fall
Mid Fall
Late Fall/Early Winter
Other details:
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:
Non-patented
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
Regional
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 allGardeners' Notes:
Rating | Content |
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Positive | 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. |
Positive | 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. |
Neutral | 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. |
Positive | On Dec 25, 2014, pmmGarak from Göppingen, 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! |
Positive | 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. |
Positive | 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. |
Positive | 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. |
Positive | 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. |
Positive | On Sep 28, 2013, Gredal from Sudbury, 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. |
Positive | 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! |
Positive | 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 |
Positive | 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. |
Negative | 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? |
Positive | 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! |
Positive | 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. |
Neutral | 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. |
Negative | 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. |
Positive | 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. |
Positive | 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!!! :-) |
Positive | 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. |
Positive | 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. |
Positive | 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. |
Positive | 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. |
Positive | 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. |
Positive | 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. |
Negative | 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. |
Neutral | 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. |
Positive | 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. |
Neutral | 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. |
Neutral | 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 |
Positive | 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. |
Neutral | 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. |
Positive | 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. |
Positive | 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. |
Positive | 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. |
Positive | 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. |
Negative | 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. |
Positive | On Jul 28, 2002, darius from So.App.Mtns., 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.) |
Positive | 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. |
Positive | 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. |