How to Grow Crystal Palace Blue
Wikimedia Commons
Crystal Palace Blue
Lobelia erinus 'Crystal Palace Blue'
flowerCrystal Palace Blue is a compact, mounding annual flower prized for its intense deep blue flowers with white or pale centers. It's a popular bedding plant and container specimen that produces abundant blooms throughout the growing season. This variety is particularly valued for its rich color and tidy habit, making it ideal for borders, edging, and hanging baskets.
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Example Crystal Palace Blue timeline · Pittsburgh, PA (Zone 6b)
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Plant Crystal Palace Blue
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 Crystal Palace Blue blooms
Around Jun 16≈ 60 days after planting
Sample dates for Pittsburgh, PA. Sign up to get exact Crystal Palace Blue dates for your own zip code.
Growing Conditions
Soil
Growing Zones
Find your zone →Thrives as an annual in all zones; performs best in zones 3-10 as a summer annual
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Seed Germination
7-14 daysTiny seeds begin sprouting under warm, moist conditions with light exposure. Seedlings are extremely delicate and barely visible initially.
Maintain soil temperature 65-75°F (18-24°C). Keep soil consistently moist. Provide bright light (no direct sun initially). Germination takes 7-14 days.
Seedling Stage
3-4 weeksSmall, fragile plants develop their first true leaves. Growth is slow during this stage. Plants remain compact and delicate.
Provide bright, indirect light. Maintain high humidity. Keep soil moist. Begin very light feeding at half strength when first true leaves appear. Handle with care.
Vegetative Growth
2-3 weeksPlants develop multiple stems and form a bushy, mounding habit. Foliage is fine-textured and green. No flowers yet, but plant structure is becoming established.
Increase light intensity gradually. Harden off seedlings before transplanting outdoors. Begin pinching tips if plants are getting leggy to encourage branching. Water consistently.
Flowering
6-12 weeks (continues until frost)Abundant small, deep blue flowers with white or pale centers appear along the stems and throughout the foliage. Plant becomes a mass of blooms. Flowering continues prolifically until frost.
Deadhead spent flowers to encourage continuous blooming. Maintain consistent moisture. Feed every 2-3 weeks with balanced or flower-focused fertilizer. Reduce nitrogen if plants become too leafy.
Decline/End of Season
Until first frostAs temperatures drop and days shorten in fall, flowering slows. Plant gradually declines as frost approaches and plant dies.
Continue deadheading as long as flowers appear. Reduce watering as temperatures cool. Remove plants after first hard frost. Save seeds if desired before pulling plants.
Companion Planting
Plan your garden →Plant with:
Avoid planting near:
Common Pests
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Spray with water to dislodge; use insecticidal soap or neem oil if infestation is severe
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Spray with strong water stream; use insecticidal soap or neem oil for severe infestations
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and
Remove by hand; use beer traps or copper barriers; apply organic slug pellets if needed
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Use yellow sticky traps; spray with insecticidal soap or neem oil; ensure good air circulation
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Improve drainage; avoid overwatering; ensure good air circulation; remove affected plants
Uses
Cut Flowers & Arrangements
CraftCrystal Palace Blue's delicate flowers add height and vibrant color to fresh floral arrangements and bouquets. The fine, airy texture makes it excellent for filling gaps in arrangements and creating movement. [source]
Container Gardening & Edging
HouseholdIts naturally compact, mounding form makes it perfect for hanging baskets, window boxes, container combinations, and border edging. The abundant blue blooms create stunning visual impact in small spaces. [source]
Pollinator Attraction
WildlifeThe small flowers attract hummingbirds, bees, and butterflies, making it valuable for supporting pollinator populations in gardens. The continuous bloom period provides extended nectar availability. [source]
Garden Design & Color
HouseholdThe intense deep blue color serves as a striking focal point or complementary accent in landscape beds and mixed borders. It pairs well with white, yellow, and silver-foliage plants. [source]
Harvest Tips
This is an ornamental flower, not harvested for consumption. Cut flowers for arrangements as desired; flowers last 5-7 days in water. For seed saving, allow some flowers to fade naturally and develop seed pods before frost; collect seeds when pods dry.
Fun Facts
- 🌱 Crystal Palace Blue was named after the famous Crystal Palace in London, reflecting its ornamental beauty and value as a premium garden plant.
- 🌱 Lobelia erinus produces thousands of tiny seeds—a single plant can generate over 6,000 seeds, making it both prolific and easy to propagate for home gardeners.
- 🌱 This plant is technically a tropical perennial but is grown as an annual in most climates. In frost-free zones and with proper indoor cultivation, it can persist year-round.
Gardening Terms
New to gardening? Learn about terms used in this guide:
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