How to Grow Jubilee Gem Cornflower
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Jubilee Gem Cornflower
Centaurea cyanus 'Jubilee Gem'
flowerJubilee Gem is a dwarf variety of cornflower (bachelor's button) prized for its compact, bushy growth and vibrant double blue flowers. This cultivar reaches only 12-15 inches tall, making it ideal for borders, containers, and small garden spaces. It blooms prolifically throughout summer and is beloved by pollinators and florists alike.
When should you plant Jubilee Gem Cornflower in your zone?
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Example Jubilee Gem Cornflower timeline · Pittsburgh, PA (Zone 6b)
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Plant Jubilee Gem Cornflower
Around Apr 17Near Pittsburgh's average last spring frost.
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Tend & protect
Late spring–summerWatering, feeding, and pest-watch reminders.
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First Jubilee Gem Cornflower blooms
Around Jun 6≈ 50 days after planting
Sample dates for Pittsburgh, PA. Sign up to get exact Jubilee Gem Cornflower dates for your own zip code.
Growing Conditions
Soil
Growing Zones
Find your zone →Zones 2-9; thrives in cool to moderate climates
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Seedling
10-14 daysTiny green leaves emerge from soil; plant is very delicate and low to ground
Keep soil lightly moist but not soggy. Provide bright light. Thin seedlings to 9 inches apart if direct seeded. Protect from slugs and excessive rain.
Vegetative Growth
3-4 weeksPlant develops true leaves and begins forming bushy, compact structure with multiple stems
Water moderately; allow soil to dry slightly between waterings. Pinch back when 4-6 inches tall to encourage bushier growth. Reduce nitrogen to avoid excessive foliage.
Bud Formation
1-2 weeksFlower buds begin appearing at branch tips; plant reaches maximum height (12-15 inches)
Maintain consistent moisture without waterlogging. Support with small stakes if needed in windy areas. Continue deadheading adjacent spent blooms to encourage bud development.
Flowering
8-12 weeks (May/June through August/September)Abundant double blue flowers bloom in profusion; petals are layered and pompom-like
Deadhead spent flowers regularly to extend blooming season into fall. Water at soil level to keep foliage dry. Apply balanced fertilizer every 2-3 weeks if desired for sustained blooms.
Seed Production & Decline
Variable; until frostIf not deadheaded, flowers fade and develop seed heads; plant energy redirects to seed production
Allow some flowers to set seed if you want self-seeding next year. Otherwise continue deadheading. Reduce watering as temperatures cool in fall. Plant naturally declines in fall/winter.
Common Pests
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Spray with strong water jet to dislodge; use insecticidal soap or neem oil for heavy infestations
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Increase humidity; spray foliage with water; apply miticide if severe
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and
Hand-pick, set beer traps, use copper tape barriers, or apply slug pellets around base
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Improve air circulation; avoid overhead watering; spray with sulfur or fungicide if needed
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Remove affected stems; improve drainage; avoid wetting foliage
Uses
Edible Flower Garnish
CulinaryCornflower petals are edible and are traditionally used as colorful, slightly sweet garnishes for salads, desserts, and beverages. The petals add visual appeal and a delicate flavor to culinary presentations. [source]
Herbal Tea
CulinaryDried cornflower petals can be brewed into a mild, floral tea traditionally believed to support eye health and reduce inflammation. The tea has a subtle, slightly sweet taste. [source]
Traditional Eye Remedy
MedicinalHistorically, cornflower has been used in folk medicine as an herbal wash or compress for tired, inflamed eyes. Some herbalists attribute this use to flavonoid compounds present in the flowers. [source]
Cut Flowers & Arrangements
CraftJubilee Gem's compact habit and prolific double blooms make it outstanding for small bouquets, container arrangements, and pressed-flower crafts. The flowers dry well for long-lasting arrangements. [source]
Pollinator Support
WildlifeCornflowers are highly attractive to bees, butterflies, and beneficial insects, making this dwarf variety an excellent choice for pollinator gardens and encouraging natural pest control. [source]
This is not medical advice. LizPlants is not a medical resource. Always consult a qualified healthcare professional before using plants medicinally.
Harvest Tips
Cut flowers in early morning when buds just begin to open for longest vase life (7-10 days). Harvest frequently to encourage continuous blooming. Remove flowers when fully open if allowing seeds to mature for next year. Cut stems at a 45-degree angle and place immediately in cool water with floral preservative.
Fun Facts
- 🌱 Cornflowers were once a common weed in grain fields across Europe, and the plant is symbolically tied to German heritage—it is the national flower of Germany.
- 🌱 The intense blue pigment in cornflower petals comes from a compound called delphinidin, which was historically used as a natural dye for textiles and artworks.
- 🌱 Jubilee Gem's dwarf, double-flowered form is a deliberate selection from classic tall cornflower varieties, making it a modern cultivar (introduced in the mid-20th century) that suits contemporary small-space gardening.
Gardening Terms
New to gardening? Learn about terms used in this guide:
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