How to Grow Red Opal Basil
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Red Opal Basil
Ocimum basilicum var. purpurascens
herbRed Opal Basil is a striking ornamental and culinary herb with deep purple-red foliage and pink flowers. It offers a similar flavor profile to green basil with peppery, slightly clove-like notes, while providing dramatic visual interest in gardens and containers. This variety is particularly prized for both cooking and decorative landscaping.
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Example Red Opal Basil timeline · Pittsburgh, PA (Zone 6b)
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Plant Red Opal Basil
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 Red Opal Basil
Around Jun 16≈ 60 days after planting
Sample dates for Pittsburgh, PA. Sign up to get exact Red Opal Basil dates for your own zip code.
Growing Conditions
Soil
Growing Zones
Find your zone →Thrives in zones 9-11; grown as annual in cooler climates (zones 3-8)
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Seedling
2-3 weeksTiny cotyledons emerge with pale purple tint, developing first true leaves with the distinctive red-purple coloration becoming visible within 1-2 weeks.
Keep soil consistently moist. Provide bright light (grow lights 3-4 inches above seedlings). Maintain temperature of 70-75°F. Thin seedlings to prevent crowding.
Vegetative
3-4 weeksPlant develops multiple stems and increasingly darker purple-red foliage. Leaves are fully colored and aromatic. Plant establishes strong root system.
Pinch off flower buds to encourage bushier growth. Provide consistent moisture and full sun. Feed with balanced fertilizer every 2-3 weeks. Remove any green-leafed reversions.
Pre-flowering
2-3 weeksPlant reaches mature height with dense foliage. Flower buds begin forming at stem tips, showing pink coloration.
Begin light harvesting of outer leaves to encourage branching. Continue pinching top buds if extended leaf production desired. Maintain consistent watering and feeding schedule.
Flowering
4-6 weeksBeautiful pink or purple flowers bloom on terminal spikes. Plant continues producing new foliage. Flowers are edible and ornamental.
Harvest flowers for culinary use or enjoy for visual appeal. Continue harvesting leaves from lower portions. Deadhead spent flowers to extend leaf production. Reduce fertilizer if desired.
Late season/Decline
Variable, until frost or declinePlant may become woody and less productive as weather cools. Growth slows significantly, flowering continues but leaf production decreases.
In cool climates, this signals end of season; plan succession planting for continuous supply. In warm zones, rejuvenate with heavy pruning. Transition to compost or bring container indoors in cool climates.
Companion Planting
Plan your garden →Plant with:
Avoid planting near:
Common Pests
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Hand-pick in early morning, use row covers on young plants, apply neem oil or insecticidal soap
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Increase humidity, mist foliage regularly, use neem oil or insecticidal soap, strong water spray
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Yellow sticky traps, insecticidal soap, neem oil, reflective mulches
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Strong water spray, insecticidal soap, neem oil, introduce beneficial insects like ladybugs
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and
(Gastropoda)
Hand-pick, copper tape barriers, beer traps, diatomaceous earth, remove debris
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Improve air circulation, reduce humidity, apply sulfur dust or neem oil, remove affected leaves
Uses
Cooking and Seasoning
CulinaryRed Opal Basil brings the classic basil peppery-clove flavor with additional depth to dishes. Use fresh in salads, pasta, vinaigrettes, and as a garnish for soups and cocktails. [source]
Infused Oils and Vinegars
CulinaryThe leaves and flowers create beautiful purple-tinted infused oils and vinegars. These are prized for both their visual appeal and unique herbal flavor in salad dressings. [source]
Ornamental and Floral Design
CraftThe deep purple-red foliage and pink flowers make Red Opal Basil excellent for decorative garden arrangements, flower arrangements, and as an ornamental edible border plant. [source]
Traditional Herbal Use
MedicinalLike other basil varieties, Red Opal Basil has been used in traditional medicine for potential anti-inflammatory and digestive properties. Makes aromatic herbal teas. [source]
Natural Pest Deterrent
HouseholdGrowing Red Opal Basil in the garden naturally repels flies, mosquitoes, and other garden pests due to its aromatic essential oils. [source]
This is not medical advice. LizPlants is not a medical resource. Always consult a qualified healthcare professional before using plants medicinally.
Harvest Tips
Begin harvesting when plant has at least 6 true leaves by pinching off the top 1-2 inches of stem. Harvest from the top down to encourage bushiness. Regular harvesting extends production. Best flavor is in morning after dew dries. Pinch off flowers to extend leaf harvest season. Can harvest continuously until frost or plant decline. For best purple color and flavor intensity, harvest in peak sunlight hours.
Fun Facts
- 🌱 Red Opal Basil's purple color comes from anthocyanin pigments, the same antioxidant compounds found in blueberries and red wine, making it both beautiful and potentially nutritious.
- 🌱 This variety was developed at the University of Connecticut Agricultural Experiment Station and introduced to the market in the 1960s, becoming the first commercially available ornamental basil cultivar.
- 🌱 Red Opal Basil flowers are completely edible and have a slightly milder, sweeter flavor than the leaves, making them prized for gourmet cuisine and garnishing high-end dishes.
Gardening Terms
New to gardening? Learn about terms used in this guide:
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