How to Grow Blue Spire
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Blue Spire
Salvia guaranitica 'Black and Blue'
herbBlue Spire is a tender perennial sage known for its striking deep blue flowers with contrasting dark purple-black calyxes, creating a dramatic bicolor effect. It grows as a bushy, upright plant and blooms prolifically from summer through fall. This aromatic herb is primarily grown as an ornamental but has culinary applications and attracts hummingbirds and bees.
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Example Blue Spire timeline · Pittsburgh, PA (Zone 6b)
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Plant Blue Spire
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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Harvest Blue Spire
Around Jun 16≈ 60 days after planting
Sample dates for Pittsburgh, PA. Sign up to get exact Blue Spire dates for your own zip code.
Growing Conditions
Soil
Growing Zones
Find your zone →Thrives in zones 9-11; grown as an annual in zones 8b and cooler
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Seedling
2-3 weeksTiny seedlings emerge with oval cotyledons and develop their first true leaves within 2-3 weeks.
Provide warmth (70-75°F), consistent moisture without waterlogging, and bright light. Bottom heat accelerates germination.
Vegetative
4-6 weeksPlant develops bushy growth with multiple stems and lance-shaped, aromatic green leaves. Height reaches 12-18 inches.
Pinch back growing tips early to encourage branching. Maintain consistent moisture and full sun exposure. Apply balanced fertilizer every 2-3 weeks.
Flowering
8-12 weeks (or until frost)Tall flower spikes emerge with tubular two-lipped flowers; calyxes are deep purple-black while flowers are bright blue. Blooming begins mid-summer.
Continue regular watering and feeding. Deadhead spent flowers to encourage continuous blooming. Support tall stems if needed.
Peak Bloom & Pollination
4-8 weeksPlant reaches maximum flowering with dense spikes of flowers attracting hummingbirds and pollinators. Seeds develop in calyxes if flowers are left unpollinated.
Reduce nitrogen fertilizer to encourage more flowers over foliage. Monitor for spider mites in dry conditions. Allow some flowers to remain for seed production if desired.
Decline & Overwintering
Variable; ongoing until springIn zones 8b, foliage dies back after frost. In warmer zones, plant becomes semi-dormant with reduced growth. Seed pods mature and dry.
In cold zones, cut back to 6 inches before frost and mulch, or dig and pot for indoor overwintering. In warm zones, reduce watering and fertilizing.
Companion Planting
Plan your garden →Plant with:
Avoid planting near:
Common Pests
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Increase humidity by misting; spray with water to dislodge; use neem oil or insecticidal soap if severe
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Yellow sticky traps; spray undersides of leaves with insecticidal soap or neem oil
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Remove with alcohol-soaked cotton swab; spray with neem oil or insecticidal soap
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Improve air circulation; avoid overhead watering; apply sulfur dust or potassium bicarbonate fungicide
Uses
Fresh Herb & Tea
CulinaryYoung leaves can be used fresh or dried to make aromatic herbal tea with a minty, slightly peppery flavor. The leaves also add visual interest and subtle flavor to cocktails and beverages. [source]
Traditional Herbal Remedy
MedicinalIn traditional South American medicine, Salvia guaranitica is used as a digestive tonic and for its antimicrobial properties. Modern herbal practitioners value it for mild anti-inflammatory and respiratory support applications. [source]
Hummingbird & Pollinator Magnet
WildlifeThe tubular blue flowers are specifically adapted to attract hummingbirds, while the open flower structure also welcomes bees and other pollinators. A single plant can draw dozens of hummingbirds in peak bloom season. [source]
Cut Flower & Fresh Arrangements
HouseholdThe dramatic flower spikes with their contrasting dark calyxes and bright blue flowers last well in vases and add bold vertical interest to fresh flower arrangements. Cut stems last 7-10 days in water. [source]
Dried Flower Crafts
CraftDried flower spikes retain their color and distinctive two-tone structure, making them excellent for dried arrangements, pressed flower crafts, and decorative dried bouquets. [source]
This is not medical advice. LizPlants is not a medical resource. Always consult a qualified healthcare professional before using plants medicinally.
Harvest Tips
Pinch or cut fresh leaves anytime for culinary use; harvest in morning after dew dries for best flavor. For ornamental use, cut flower stems when most buds are open. Leave some flowers to mature for seed collection in fall. In cold zones, harvest before first frost for preserving.
Fun Facts
- 🌱 Blue Spire's common name 'Black and Blue' refers to the striking bicolor effect of the dark purple-black calyxes contrasting with brilliant azure flowers—this dramatic pairing is uncommon in the Salvia genus.
- 🌱 The plant is native to South America and was traditionally used by Guaraní peoples as both a medicinal herb and for ceremonial purposes before becoming popular in ornamental horticulture.
- 🌱 A single established Blue Spire plant can attract over 100 hummingbirds per day during peak bloom season, making it one of the most effective hummingbird magnets in the garden.
Gardening Terms
New to gardening? Learn about terms used in this guide:
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