Blue Cornflower
Centaurea cyanus 'Blue Diadem'
Not currently listed at our partner nurseries.
Essentials
At a Glance
Plant Type
Annual
Height
24 inches
Width
12 inches
Light
Full Sun, Partial Sun
Zones
4, 5, 6, 7, 8, 9
Water
Moderate
Humidity
Average
Lifespan
Annual
Native To
Europe
Toxicity
Non-toxic
The Story
Plant Bio
Annual flowering plant known for its bright blue flowers. Unique cultivar with especially vivid blue blooms and long blooming period.
Bloom Period:
Uses & Benefits:
Marketplace
Where to Buy
We couldn't find this plant listed online right now.
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Planting
How to Grow
- Tuck seeds into well-draining soil in early spring for best germination.
- Mist cuttings lightly to maintain soil moisture during propagation.
- Thin seedlings to prevent overcrowding and promote healthy growth.
- Fertilize monthly with a balanced, water-soluble fertilizer during the growing season.
- Pinch back young plants to encourage bushier growth and more flowers.
- Deadhead spent blooms regularly to prolong flowering period.
Pro Tip
Sow seeds directly outdoors for vibrant blooms and natural growth.
Keep It Thriving
Care Guide
Do
- Water regularly but avoid overwatering 🌱
- Provide full sun for optimal flowering
- Deadhead to encourage continuous blooms
- Apply organic compost annually for nutrient boost
- Mulch to retain soil moisture
Don't
- Avoid overwatering to prevent root rot ❌
- Don’t plant in shady areas which reduce flowering
- Refrain from heavy fertilizing late in the season
- Don’t forget to remove weeds around the plant
- Avoid disturbing roots during watering
Seasonal Care Calendar
| Task | Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec |
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Deadhead | ||||||||||||
| Fertilize | ||||||||||||
| Harvest | ||||||||||||
| Plant |
Watch Out For
Pests & Diseases
Common Pests
Common Diseases
In the Garden
Landscape Uses & Companions
Landscape Uses
Companion Plants
Multiply
Propagation Methods
Good to Know
Common Questions
Blue Cornflower questions
What zones can Blue Cornflower grow in?
Blue Cornflower is hardy in USDA Zones 4–10. Inside that range it survives winter in the ground; outside it, grow it as an annual or a container plant you protect.
Is Blue Cornflower deer resistant?
Yes — Blue Cornflower is rated deer-resistant. Deer typically pass it over, though extreme hunger can override any plant's defenses.
When does Blue Cornflower bloom?
Blue Cornflower typically blooms in late spring through early summer. Exact timing shifts a week or two with your zone — Sow's bloom calendar maps it to your garden.
Does Blue Cornflower need full sun?
Blue Cornflower does best in full sun to part shade. In hot climates, afternoon shade keeps blooms fresher longer.
Is Blue Cornflower drought tolerant?
Yes — once established (usually after the first full season), Blue Cornflower handles dry spells with minimal watering. Water deeply its first year to build the root system that makes that possible.
More Centaurea to compare
Amethyst in Snow Bachelor's Button
Centaurea cyanus 'Amethyst in Snow'
Cornflower Bachelor's Button
Centaurea cyanus 'Bachelor's Button'
Red Boy Cornflower
Centaurea cyanus 'Red Boy'
Amethyst Dream Cornflower
Centaurea cyanus 'Amethyst Dream'
Black Gem Cornflower
Centaurea cyanus 'Black Gem'
Bachelor's Button Blue Boy
Centaurea cyanus 'Blue Boy'
Keep exploring
Explore the genus
Collections featuring this plant
Grow Blue Cornflower with confidence
See it in a design of your actual yard, get zone-matched care reminders, and track it season by season in your garden journal.
