How to Grow Blanket Sage Deep Blue
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Blanket Sage Deep Blue
Salvia × superba 'Deep Blue'
flowerBlanket Sage Deep Blue is a compact, ornamental flowering perennial prized for its rich deep blue-purple flower spikes that rise above silvery-green foliage. This hybrid salvia cultivar produces long-lasting blooms throughout the growing season and attracts pollinators while requiring minimal maintenance. It's an excellent choice for borders, containers, and Mediterranean-style gardens.
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Example Blanket Sage Deep Blue timeline · Pittsburgh, PA (Zone 6b)
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Plant Blanket Sage Deep 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 Blanket Sage Deep Blue blooms
Around Jun 16≈ 60 days after planting
Sample dates for Pittsburgh, PA. Sign up to get exact Blanket Sage Deep Blue dates for your own zip code.
Growing Conditions
Soil
Growing Zones
Find your zone →Thrives in zones 4-9; prefers cooler climates and struggles in hot, humid summers
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Seedling
2-3 weeksTiny seedlings with first true leaves emerging; very delicate and vulnerable to damping off
Keep soil consistently moist but not waterlogged. Provide bright light. Maintain warm temperatures (70-75°F). Ensure excellent air circulation.
Vegetative Growth
4-6 weeksPlant develops rosette of silvery-green, lance-shaped leaves; bushy growth with no flowers yet
Pinch back tips when 4-6 inches tall to encourage branching. Water moderately. Fertilize lightly with balanced fertilizer every 3-4 weeks.
Budding
2-3 weeksFlower spikes begin to form at stem terminals; buds are compact and clustered
Increase watering slightly during bud development. Continue deadheading any weak or malformed buds. Avoid high-nitrogen fertilizer.
Flowering
6-10 weeks (with deadheading, can extend to 12+ weeks)Dense spikes of deep blue-purple tubular flowers open sequentially from bottom to top, creating long bloom display
Deadhead spent flower spikes regularly to encourage continuous blooming. Water consistently but allow surface to dry. Avoid overhead watering.
Post-Bloom/Dormancy
4-8 weeks until dormancyFlowers fade and seed heads form; foliage may decline in heat or remain attractive
Cut back to 6 inches in fall after hard frost or in early spring. In mild climates, prune lightly after first flush to encourage reblooming. Divide every 3-4 years.
Companion Planting
Plan your garden →Plant with:
Avoid planting near:
Common Pests
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Ensure good air circulation; avoid wetting foliage; remove affected leaves; apply sulfur fungicide in early stages if needed
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Increase humidity with occasional misting; spray with neem oil or insecticidal soap; remove heavily infested leaves
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and
Hand-pick at dusk; use copper tape barriers; apply diatomaceous earth around base; beer traps; remove debris and mulch heavily
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Improve air circulation; remove affected foliage; avoid overhead watering; apply copper fungicide if severe
Uses
Tea and Herbal Infusions
CulinarySalvia species have been traditionally used to make herbal teas with mild sage-like flavor, though Deep Blue is primarily ornamental and less commonly used than culinary sage varieties. The flowers are edible and can garnish salads or beverages. [source]
Pollinator Attraction
WildlifeThe deep blue flower spikes are irresistible to bees, hummingbirds, and butterflies, making it an excellent choice for pollinator gardens and attracting beneficial insects throughout the blooming season. [source]
Cut and Dried Flowers
CraftThe long-lasting flower spikes dry exceptionally well, retaining their rich blue color and form. Harvest at peak bloom and hang-dry upside down in a warm, dark location for use in dried arrangements, wreaths, and craft projects. [source]
Ornamental Garden Design
HouseholdDeep Blue Blanket Sage serves as an excellent structural element in borders, cottage gardens, and Mediterranean-style landscapes, providing height, color contrast, and extended seasonal interest from early summer through fall. [source]
Traditional Herbal Use
MedicinalLike other Salvia species, it contains compounds traditionally believed to have anti-inflammatory and antimicrobial properties, though Deep Blue cultivars are grown primarily for ornamental value rather than medicinal harvest. [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 flower spikes when approximately 1/3 to 1/2 of florets are open for longest vase life (7-10 days). Harvest in early morning when stems are turgid. Deadhead spent flowers regularly throughout the season to promote continuous blooming. In fall, cut back entire plant to 6 inches after frost or late frost.
Fun Facts
- 🌱 The name 'Blanket Sage' refers to how the plant's profuse flowering can blanket an entire garden area with color when planted in mass groupings, creating stunning visual impact.
- 🌱 Blanket Sage Deep Blue is a hybrid (Salvia × superba) derived from crossing European Salvia pratensis and Asian Salvia nemorosa, combining the best traits of both parent species for superior ornamental qualities.
- 🌱 This cultivar is one of the most cold-hardy salvias available and was bred for improved heat and drought tolerance compared to species salvias, making it reliable across a wide range of North American climates.
Gardening Terms
New to gardening? Learn about terms used in this guide:
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