Centaurea, Bachelor's Button, Cornflower 'Blue Diadem'

Centaureacyanus

Family
Asteraceae (ass-ter-AY-see-ee)
Genus
Centaurea (sen-TAR-ee-uh)
Species
cyanus (SY-an-us)
Synonym
Sun Exposure
Full Sun
Foliage
Herbaceous
Succulent
Height
24-36 in. (60-90 cm)
Spacing
6-9 in. (15-22 cm)
Hardiness
Not Applicable
Danger
N/A
Bloom Color
Dark Blue
Bloom Time
Late Spring/Early Summer
Mid Summer
Late Summer/Early Fall
Other Details
Category
Annuals
Water Requirements
Average Water Needs; Water regularly; do not overwater
Foliage Color
Bronze
Blue-Green
Where to Grow
Bloom Characteristics
Flowers are good for drying and preserving
This plant is attractive to bees, butterflies and/or birds
Bloom Size
Other details
Soil pH requirements
7.6 to 7.8 (mildly alkaline)
7.9 to 8.5 (alkaline)
Patent Information
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
Self-sows freely; deadhead if you do not want volunteer seedlings next season
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
Regional

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

Redwood City, California

Richmond, California

San Jose, California

Washington, Missouri

Charleston, West Virginia

Madison, Wisconsin

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Gardener's Notes:

2
positives
0
neutral
0
negative
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R
Madison, WI (Zone 5a) | September 2007 | positive

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 sta...Read More

L
Ogden, UT (Zone 5b) | January 2005 | positive

This tall cornflower has striking, bright blue, double flowers and silvery-green foliage. 'Blue Diadem' has larger flowers than most var...Read More

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