Centaurea Species, Mountain Bluet, Mountain Cornflower, Perennial Cornflower

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 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 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 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 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 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 morethe parking strip by the street. Zone 8.

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 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 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 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 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 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 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 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 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 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 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.

Sandy

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 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 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