Photo by Melody
We rolled out several small fixes on January 29. If you encounter any problems, please report them in the designated thread in the DG Site Updates forum.

PlantFiles: Bachelor's Button, Cornflower
Centaurea cyanus 'Blue Diadem'

Family: Asteraceae (ass-ter-AY-see-ee) (Info)
Genus: Centaurea (sen-TAR-ee-uh) (Info)
Species: cyanus (SY-an-us) (Info)
Cultivar: Blue Diadem

One vendor has this plant for sale.

3 members have or want this plant for trade.


24-36 in. (60-90 cm)

6-9 in. (15-22 cm)

Not Applicable

Sun Exposure:
Full Sun


Bloom Color:
Medium Blue

Bloom Time:
Late Spring/Early Summer
Mid Summer
Late Summer/Early Fall


Other details:
This plant is attractive to bees, butterflies and/or birds
Average Water Needs; Water regularly; do not overwater
Self-sows freely; deadhead if you do not want volunteer seedlings next season
Flowers are good for drying and preserving

Soil pH requirements:
7.6 to 7.8 (mildly alkaline)
7.9 to 8.5 (alkaline)

Patent Information:
Unknown - Tell us

Propagation Methods:
From seed; direct sow outdoors in fall
From seed; winter sow in vented containers, coldframe or unheated greenhouse
From seed; sow indoors before last frost
From seed; direct sow after last frost

Seed Collecting:
Collect seedhead/pod when flowers fade; allow to dry
Allow seedheads to dry on plants; remove and collect seeds
Properly cleaned, seed can be successfully stored

Click thumbnail
to view:

By LilyLover_UT
Thumbnail #1 of Centaurea cyanus by LilyLover_UT

By rebecca101
Thumbnail #2 of Centaurea cyanus by rebecca101

By Calif_Sue
Thumbnail #3 of Centaurea cyanus by Calif_Sue

By Calif_Sue
Thumbnail #4 of Centaurea cyanus by Calif_Sue

By Calif_Sue
Thumbnail #5 of Centaurea cyanus by Calif_Sue

By AnniesAnnuals
Thumbnail #6 of Centaurea cyanus by AnniesAnnuals

By AnniesAnnuals
Thumbnail #7 of Centaurea cyanus by AnniesAnnuals


2 positives
No neutrals
No negatives

Gardeners' Notes:

Positive rebecca101 On Sep 26, 2007, rebecca101 from Madison, WI (Zone 5a) wrote:

This was a very fine bachelor's button, although overall I'd say not worth the extra $$ I shelled out for it as compared to the cheap standard varieties. The flowers on Blue Diadem are a bit more refined looking - they're flatter and somewhat larger. A lovely shade of blue. I didn't find them to be as large as advertised though (the source I bought them from claimed they get to be 4" across - mine were nowhere near that.)

Positive LilyLover_UT On Jan 16, 2005, LilyLover_UT from Ogden, UT (Zone 5b) wrote:

This tall cornflower has striking, bright blue, double flowers and silvery-green foliage. 'Blue Diadem' has larger flowers than most varieties. Cornflowers attract a wide range of beneficial insects.


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

Redwood City, California
Richmond, California
San Jose, California
Charleston, West Virginia
Madison, 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