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Centaurea cyanus ‘Blue Diadem’ (Cornflower)

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

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

Bearing charming and profuse flowers for months, Centaurea cyanus ‘Blue Diadem’ (Cornflower) is an attractive annual with sky blue double flowers adorned with dark purple stamens. Blooming abundantly from spring to early fall, the blossoms rise cheerfully atop branching stems clad with lance-shaped, silvery-green leaves. Attracting bees, butterflies and other admirers, this cornflower is excellent for cutting.

  • Grow up to 30 in. tall (75 cm) and 10 in. wide (25 cm). 
  • Prefer full sun or light shade and enjoy average, medium, well-drained soils. Cornflowers are very adaptable and will grow in the poorest of soils. Plant will tend to flop in too much shade. Staking may be required on taller plants. Minimal watering and no fertilizer are required to keep these annuals going. Established plants can tolerate dry soil, but regular watering will keep the plants healthier.
  • Easy to grow and virtually pest and disease free (watch for aphids and mealybugs), they are also deer and drought tolerant!
  • Perfect for borders and beds, cottage gardens, prairie plantings, cutting gardens, wildlife gardens or containers. Great as cut flowers too, fresh or in dried arrangements!
  • New plants may be grown each year by planting seed indoors 6-8 weeks before the last spring frost date or outdoors at the last spring frost date. In mild winter areas, seed may be planted outdoors in the fall.
  • Plants may reseed in the garden. Deadheading spent flowers will help prevent undesired self-seeding
  • Centaurea cyanus species is native to Europe.
  • Find where this species is invasive in the United States.
  • Discover beautiful U.S. native plant alternatives.

Requirements

Hardiness 2 - 11
Heat Zones 1 - 7
Climate Zones 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, H1, H2
Plant Type Annuals
Plant Family Compositae
Genus Centaurea
Common names Bachelor's Button, Cornflower
Exposure Full Sun
Season of Interest Spring (Late)
Summer (Early, Mid, Late)
Height 2' - 3'
(60cm - 90cm)
Spread 8" - 10"
(20cm - 25cm)
Spacing 10" (25cm)
Maintenance Low
Water Needs Average
Soil Type Chalk, Loam, Sand
Soil pH Acid, Alkaline, Neutral
Soil Drainage Well-Drained
Characteristics Cut Flowers, Showy
Tolerance Drought, Deer
Attracts Bees, Birds, Butterflies
Garden Uses Beds And Borders, Patio And Containers
Garden Styles Prairie and Meadow, Informal and Cottage, Gravel and Rock Garden, Cutting Garden, Coastal Garden
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Alternative Plants to Consider

Centaurea cyanus ‘Snowman’ (Cornflower)
Centaurea dealbata (Persian Cornflower)
Centaurea dealbata ‘John Coutts’ (Persian Cornflower)
Centaurea cyanus ‘Black Gem’ (Cornflower)
Centaurea cyanus ‘Pinkie’ (Cornflower)
Centaurea cyanus ‘Jubilee Gem’ (Cornflower)

Recommended Companion Plants

Papaver rhoeas (Flanders Poppy)
Ammi visnaga (Toothpick Weed)
Salvia horminum ‘Pink Sunday’ (Annual Sage)
Eschscholzia californica (California Poppy)

Find In One of Our Guides or Gardens

Stunning Blue Flowers to Enhance Your Garden’s Beauty
Best Annual Flowers and Plants to Spruce up Your Garden
Companion Planting With Annuals
Native Plant Alternatives to Centaurea cyanus (Cornflower)
While every effort has been made to describe these plants accurately, please keep in mind that height, bloom time, and color may differ in various climates. The description of these plants has been written based on numerous outside resources.
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Requirements

Hardiness 2 - 11
Heat Zones 1 - 7
Climate Zones 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, H1, H2
Plant Type Annuals
Plant Family Compositae
Genus Centaurea
Common names Bachelor's Button, Cornflower
Exposure Full Sun
Season of Interest Spring (Late)
Summer (Early, Mid, Late)
Height 2' - 3'
(60cm - 90cm)
Spread 8" - 10"
(20cm - 25cm)
Spacing 10" (25cm)
Maintenance Low
Water Needs Average
Soil Type Chalk, Loam, Sand
Soil pH Acid, Alkaline, Neutral
Soil Drainage Well-Drained
Characteristics Cut Flowers, Showy
Tolerance Drought, Deer
Attracts Bees, Birds, Butterflies
Garden Uses Beds And Borders, Patio And Containers
Garden Styles Prairie and Meadow, Informal and Cottage, Gravel and Rock Garden, Cutting Garden, Coastal Garden
How Many Plants
Do I Need?
Explore Great Plant Combination Ideas
Centaurea
Guides with
Centaurea
Not sure which Centaurea to pick?
Compare Now

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