How to Grow Summer Skies Delphinium
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Summer Skies Delphinium
Delphinium elatum 'Summer Skies'
flowerSummer Skies is a stunning cultivar of tall delphinium featuring striking blue flowers with white and purple centers arranged in dense spikes. This perennial blooms mid-summer and can reach 3-4 feet tall, providing dramatic vertical interest and cut flowers for arrangements. It's prized for its vibrant color and impressive flower spikes that brighten gardens and borders.
When should you plant Summer Skies Delphinium in your zone?
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Example Summer Skies Delphinium timeline · Pittsburgh, PA (Zone 6b)
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Plant Summer Skies Delphinium
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 Summer Skies Delphinium blooms
Around Jul 1≈ 75 days after planting
Sample dates for Pittsburgh, PA. Sign up to get exact Summer Skies Delphinium dates for your own zip code.
Growing Conditions
Soil
Growing Zones
Find your zone →Thrives in zones 2-6; prefers cooler climates with distinct seasons
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Seedling
3-4 weeksTiny seedlings with 2-4 true leaves emerge within 14-21 days; plants are delicate and small
Provide bright light, maintain consistent moisture without waterlogging, keep temperatures cool (60-65°F). Bottom heat can improve germination but is not required.
Vegetative Growth
4-6 weeksPlants develop true leaves and sturdy stems; foliage becomes deeply lobed and fern-like; growth accelerates as plants establish
Thin seedlings to proper spacing, harden off gradually before transplanting outdoors, stake or support plants that will exceed 2 feet. Pinch center stems in early growth to encourage bushier form if desired.
Bud Formation
2-3 weeksDense flower buds form along tall central spikes; buds are tightly clustered and still green to purple
Ensure consistent moisture and apply balanced fertilizer; provide sturdy stakes and tie-offs as plant grows taller. Remove dead foliage to improve air circulation.
Flowering
4-6 weeksStunning dense spikes of brilliant blue flowers with white and purple centers open from bottom to top; flowers are fully double or semi-double depending on cultivar
Deadhead spent flowers to encourage secondary blooms; maintain consistent watering; provide full sun for best color. Remove entire spent spike after flowering to promote reblooming in late summer.
Seed Development & Dormancy
Ongoing through fall/winterFlowers fade and seed pods develop; foliage may decline as plant conserves energy for winter survival in perennial cycle
Allow some flowers to set seed if desired for self-seeding; cut back dead foliage in fall after first frost. Apply winter mulch (2-3 inches) in colder zones to protect crowns.
Companion Planting
Plan your garden →Plant with:
Avoid planting near:
Common Pests
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Spray with strong water spray; use sulfur-based miticide if severe; improve air circulation
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Spray with insecticidal soap or neem oil; encourage beneficial insects like ladybugs
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and
Handpick in early morning or evening; use copper barriers; apply organic slug bait around base
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Ensure good air circulation, avoid overhead watering; apply fungicide if needed; remove affected leaves
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Remove infected foliage promptly; apply fungicide; maintain dry foliage by watering at base only
Uses
Ornamental garnish (decorative only)
CulinaryWhile delphinium flowers are highly toxic and not edible, their striking blooms are used by professional florists as ornamental garnish in upscale food presentations where flowers are removed before consumption. They add dramatic visual height and color to floral centerpieces. [source]
Cut flower arrangements and dried flowers
CraftSummer Skies delphiniums are prized cut flowers for floral arrangements, providing dramatic height and bold color. They also dry beautifully for permanent arrangements when hung upside-down in a warm, dark location. [source]
Garden backdrop and focal point planting
HouseholdThe tall, striking blue spikes make Summer Skies delphiniums ideal for creating vertical emphasis and dramatic garden backdrops in borders, cottage gardens, and perennial beds. They work well as a focal point or massed planting. [source]
Historical medicinal uses (now deprecated)
MedicinalDelphiniums were traditionally used in herbal medicine, but are highly toxic alkaloid-containing plants and should never be ingested or used for medicinal purposes. Modern gardening treats them purely as ornamental flowers. [source]
Pollinator attraction
WildlifeThe tall flower spikes attract bees, butterflies, and other beneficial pollinators to the garden, making them valuable for ecological gardens and supporting local pollinator populations. [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 stems are fully hydrated; harvest when lower flowers on spike are open but upper buds still tight for longest vase life (7-10 days with stem conditioning). For fresh arrangements, cut tall spikes at base. Deadhead spent flowers on living plants to encourage more blooms. Seeds can be collected by allowing flowers to dry on plant, then cutting spikes and storing in dry conditions.
Fun Facts
- 🌱 Summer Skies delphinium is highly toxic to humans and pets; all parts of the plant contain harmful alkaloids and should never be ingested or handled excessively without gloves.
- 🌱 The name 'delphinium' comes from the Greek word 'dolphin,' as the flower buds were thought to resemble the shape of a dolphin's head.
- 🌱 These delphiniums can live 5-7 years in the garden if properly cared for and cut back annually; they are short-lived perennials that benefit from division every 3-4 years to maintain vigor.
Gardening Terms
New to gardening? Learn about terms used in this guide:
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