How to Grow Royal Blue
Royal Blue
Salvia farinacea 'Royal Blue'
flowerRoyal Blue is a cultivar of mealy sage featuring stunning deep blue flower spikes that rise above silvery-green foliage. This tender perennial is commonly grown as an annual and produces continuous blooms throughout the growing season. It's excellent for borders, containers, and cut flower arrangements.
When should you plant Royal Blue in your zone?
Get a personalized planting timeline — when to start seeds, transplant, and harvest — based on your USDA zone and local frost dates. Free to start.
Example Royal Blue timeline · Pittsburgh, PA (Zone 6b)
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Plant Royal 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 Royal Blue blooms
Around Jun 26≈ 70 days after planting
Sample dates for Pittsburgh, PA. Sign up to get exact Royal Blue dates for your own zip code.
Growing Conditions
Soil
Growing Zones
Find your zone →Thrives in zones 8-11; grown as annual in cooler zones
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Seedling
2-3 weeksSmall green leaves emerge with fine silvery hairs beginning to develop on stems. Plants are delicate and low-growing.
Keep soil consistently moist but not waterlogged. Provide bright light. Thin seedlings to proper spacing once they have 2-3 true leaves.
Vegetative
3-4 weeksPlant develops bushy growth with increasingly silvery foliage. Stems strengthen and branch out. No flowers yet.
Continue moderate watering. Pinch back growing tips early to encourage bushier form. Apply balanced fertilizer every 2-3 weeks.
Flowering
8-12 weeks (throughout season with deadheading)Deep blue flower spikes emerge from the foliage, with small tubular flowers arranged densely on upright stems. Plant becomes increasingly ornamental.
Deadhead spent flowers regularly to promote continuous blooming. Maintain consistent watering. Switch to lower-nitrogen fertilizer to support flowering.
Peak Bloom
6-8 weeks or until first frost in cold climatesPlant is covered in multiple deep blue flower spikes at various heights. Silvery foliage creates striking contrast with intense blue flowers.
Deadhead consistently. Provide afternoon shade in hottest climates. Water deeply once weekly. Remove any yellowing leaves.
Late Season/Decline
4-6 weeks until frost or end of seasonFlowering slows as temperatures drop or plants age. Some foliage may yellow. In zones 8+, plant may persist through winter.
Reduce watering. Allow some flowers to remain for seed collection if desired. Cut back plant by half in fall or spring (zone 8+) for renewal.
Companion Planting
Plan your garden →Plant with:
Avoid planting near:
Common Pests
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Increase humidity with misting, spray with neem oil or insecticidal soap weekly for 2-3 weeks
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Use yellow sticky traps, spray undersides of leaves with insecticidal soap or neem oil
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Improve air circulation, avoid overhead watering, apply sulfur dust or baking soda spray
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Ensure excellent drainage, do not overwater, remove affected plants
Uses
Floral Garnish
CulinaryRoyal Blue flowers are edible with a slightly sweet, herbaceous flavor and can be used as an elegant garnish for salads, desserts, and beverages. [source]
Cut Flowers & Arrangements
CraftThe long-lasting blue spikes are excellent for fresh and dried flower arrangements, adding height and striking color to bouquets and floral designs. [source]
Traditional Herbal Use
MedicinalSalvia species have been used in traditional medicine for their potential anti-inflammatory and antioxidant properties, though culinary application is more common. [source]
Pollinator Attractor
WildlifeThe nectar-rich flowers attract hummingbirds, bees, and butterflies throughout the growing season, making it valuable for pollinator gardens. [source]
Ornamental Garden Display
HouseholdRoyal Blue's compact growth habit and abundant flowers make it ideal for border edging, containers, raised beds, and landscape focal points. [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 stems when 2-3 flowers on the spike have opened for cut arrangements. Cut above a leaf node to encourage branching. Flowers last 7-10 days in a vase. For seed collection, allow some flower spikes to mature and dry on the plant; collect seeds when pods turn brown.
Fun Facts
- 🌱 Royal Blue is also called 'Mealy Sage' because its stems and leaves are covered with fine silvery powder (farina means 'mealy flour' in Latin), which helps reflect heat and reduces water loss.
- 🌱 While typically grown as an annual in cold climates, Royal Blue can become a perennial shrub in warm zones 8-11, returning year after year with proper care.
- 🌱 The flower spikes can grow up to 18-24 inches tall on mature plants, making them excellent for adding height and vertical interest to garden designs.
Gardening Terms
New to gardening? Learn about terms used in this guide:
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