How to Grow Salvia 'Indigo Spires'
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Salvia 'Indigo Spires'
Salvia longispicata × Salvia farinacea
flowerIndigo Spires is a hybrid salvia cultivar known for its striking deep blue-purple flower spikes that bloom prolifically from summer through fall. This tender perennial shrub grows as an upright, compact plant with aromatic foliage and attracts hummingbirds and pollinators. It is valued for its extended blooming season and ornamental appeal in borders, containers, and cottage gardens.
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Example Salvia 'Indigo Spires' timeline · Pittsburgh, PA (Zone 6b)
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Plant Salvia 'Indigo Spires'
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 Salvia 'Indigo Spires' blooms
Around Jun 16≈ 60 days after planting
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Growing Conditions
Soil
Growing Zones
Find your zone →Zones 8-11; grown as an annual in cooler zones or protected in winter
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Establishment
2-3 weeksYoung transplants are developing their root system and initial foliage; plants appear compact with only a few leaves.
Water regularly to keep soil consistently moist but not waterlogged. Pinch tips early to encourage branching. Protect from strong winds.
Vegetative Growth
4-6 weeksPlant grows taller and fuller with dense, aromatic gray-green foliage; branching increases significantly.
Continue pinching or light pruning to promote bushier growth. Apply balanced fertilizer every 2-3 weeks. Ensure good drainage and air circulation.
Budding & Early Flowering
2-3 weeksDeep indigo-blue flower spikes begin to form at branch tips; buds elongate into flower candles.
Reduce nitrogen fertilizer; switch to bloom-promoting formula (higher phosphorus and potassium). Continue moderate watering. Deadhead spent flowers to encourage more blooms.
Peak Bloom
8-12 weeks (or longer with deadheading)Plant is covered with multiple deep blue-purple flower spikes in full bloom; foliage is lush and aromatic.
Deadhead regularly to extend blooming. Water at soil level to avoid wetting foliage (prevents mildew). Feed with diluted bloom fertilizer every 2 weeks.
Fall & Dormancy
Varies by climate; 4-8 weeksFlowering may slow in late fall; in zones 8-9, plant may decline with frost. In warmer zones, may continue blooming into winter.
In frost-prone areas, cut back by 1/3 in fall or protect with mulch. In zone 11+, light pruning maintains shape. Stop heavy fertilizing.
Companion Planting
Plan your garden →Plant with:
Avoid planting near:
Common Pests
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Spray with water to dislodge; use miticide if severe. Increase humidity and air circulation. Avoid overhead watering.
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Use yellow sticky traps; spray with insecticidal soap or neem oil. Remove heavily infested leaves.
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Improve air circulation; avoid wetting foliage. Apply sulfur dust or baking soda spray. Remove affected leaves.
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and
Hand-pick in early morning or evening. Use beer traps or copper barriers. Remove debris and dense ground cover nearby.
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Hand-pick visible caterpillars. Use Bt (Bacillus thuringiensis) spray for light infestations.
Uses
Garden color & hummingbird attraction
OrnamentalThe deep indigo-blue flower spikes provide striking vertical color in borders and containers from summer through fall. The flowers are highly attractive to hummingbirds, butterflies, and other pollinators. [source]
Edible flowers for garnish
CulinaryThe individual salvia flowers are edible and can be used to garnish salads, desserts, and beverages. They add a subtle, slightly minty flavor and striking color. [source]
Cut & dried flower arrangements
CraftThe tall, slender flower spikes are excellent for fresh and dried arrangements. They dry well and maintain their color, making them valuable for floral crafts and long-lasting bouquets. [source]
Herbal tea & traditional remedies
MedicinalSalvia species have been used in traditional medicine for sore throats, digestion, and as a mild cognitive aid. While Indigo Spires is primarily ornamental, the foliage can be dried and steeped for herbal infusions. [source]
Pollinator garden support
WildlifeA key plant for supporting native bees, butterflies, and hummingbirds, especially in late summer and fall when other nectar sources may be scarce. Provides food during critical migration periods. [source]
This is not medical advice. LizPlants is not a medical resource. Always consult a qualified healthcare professional before using plants medicinally.
Harvest Tips
Indigo Spires is grown ornamentally rather than harvested in the traditional sense. Deadhead spent flower spikes regularly (pinch or cut just below the faded bloom) to encourage continuous flowering throughout the season. Cut fresh flowers for arrangements mid-morning after dew dries. For dried flowers, cut spikes when fully colored but still fresh, hang upside down in a cool, dark place for 2-3 weeks.
Fun Facts
- 🌱 Salvia 'Indigo Spires' is a hybrid cross between Salvia longispicata and Salvia farinacea, combining traits from both parent species to create an exceptionally long blooming period.
- 🌱 The name 'Indigo Spires' perfectly describes the flower form: the blooms grow along tall, spike-like inflorescences in a rich indigo-blue color that deepens as flowers mature.
- 🌱 In mild winter zones (9-11), Indigo Spires can be pruned in late winter and will regrow vigorously, often producing a bushier, more floriferous plant in its second year.
Gardening Terms
New to gardening? Learn about terms used in this guide:
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