How to Grow Magnus Basil

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Magnus Basil

Ocimum basilicum 'Magnus'

herb

Magnus is a large-leafed basil cultivar known for its deep purple foliage and robust flavor profile that combines traditional basil notes with subtle peppery undertones. It grows as a compact, bushy annual that produces abundantly throughout the growing season. This ornamental yet culinary herb is prized by chefs and gardeners for both its striking appearance and superior taste.

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Example Magnus Basil timeline · Pittsburgh, PA (Zone 6b)

Plant Magnus Basil
Around Apr 17

Near Pittsburgh's average last spring frost.
Tend & protect
Late spring–summer

Watering, feeding, and pest-watch reminders.
Harvest Magnus Basil
Around Jun 6

≈ 50 days after planting

Sample dates for Pittsburgh, PA. Sign up to get exact Magnus Basil dates for your own zip code.

Growing Conditions

☀️

Sun: Full sun, 6-8 hours daily minimum; 8+ hours preferred for best flavor and color

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Water: Keep soil consistently moist but not waterlogged; water at soil level to avoid fungal issues. Requires 1-1.5 inches per week. More frequent watering needed in hot weather and containers.

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Spacing: 12-18 inches apart inches

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Days to maturity: 50-70 days from transplant to first significant harvest

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Planting depth: Seeds: 0.25 inches deep; Transplants: at soil level (same depth as pot)

Soil

Type: Rich, well-draining loamy soil with organic matter

pH: 6.0-7.0

Amendments:

Compost well-rotted manure peat moss or coconut coir perlite for drainage

Growing Zones

Find your zone →

Annual in all zones; thrives in zones 5-10 when grown outdoors, zones 3-4 as summer annual or in containers

3a 3b 4a 4b 4c 5a 5b 5c 6a 6b 6c 7a 7b 7c 8a 8b 8c 9a 9b 10a 10b 11a

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Growth Stages

Seedling

2-3 weeks

Small cotyledons emerge; true leaves begin forming. Plant is delicate with thin stems and minimal foliage.

Keep soil warm (70-75°F) and consistently moist. Provide bright light to prevent leggy growth. Thin seedlings to prevent crowding. No fertilizer needed at this stage.

Vegetative Growth

3-4 weeks

Stems thicken and branch; distinctive purple foliage develops; plant becomes bushier with rapid leaf expansion. Height reaches 8-12 inches.

Pinch growing tips frequently to encourage branching and prevent premature flowering. Provide balanced fertilizer every 2-3 weeks. Ensure consistent moisture and full sun exposure.

Pre-flowering

2-3 weeks

Plant continues growing in size; leaf production is abundant. First flower buds may begin forming at stem tips.

Continue pinching flower buds to prolong leaf production and harvest window. Maintain regular watering and fertilizing. Monitor for pests and diseases.

Flowering & Fruiting

4-8 weeks (ongoing if managed for foliage)

Purple flower spikes emerge from stem tips; small tubular flowers bloom in whorls. Seeds develop if flowers are left unpinched.

Pinch flowers for continued leaf production, or allow some to flower for pollinator attraction. If seed saving is desired, leave select flowers to mature. Water consistently as plants flower prolifically.

Decline/End of Season

Variable; ends with frost

Plant becomes woody and produces fewer leaves; foliage quality diminishes in late summer/fall; growth slows in cooler temperatures.

Pull plants after frost (first freeze kills basil). Cut back stems before decline if re-sprouting is desired in mild climates. Save seeds from healthiest plants before plant dies.

Companion Planting

Plan your garden →

Plant with:

Tomato Pepper Eggplant Thyme Oregano Parsley Onion Garlic Marigold Nasturtium

Avoid planting near:

Rue Fennel Dill Anise

Common Pests

Hand-pick in early morning; use neem oil spray; plant repellent herbs nearby like tansy or garlic
Spray with insecticidal soap; use yellow sticky traps; spray undersides of leaves; increase air circulation
Mist leaves regularly to increase humidity; spray with neem oil; use insecticidal soap; ensure good air circulation
Spray with strong water stream; use insecticidal soap; release ladybugs; neem oil application
Use blue/yellow sticky traps; spray neem oil weekly; remove heavily infested leaves; improve air circulation
Water at soil level, not on foliage; improve air circulation; remove infected leaves; apply fungicide if severe; avoid overhead watering

Uses

🍳

Fresh Cooking & Pesto

Culinary

Magnus basil's large leaves and robust, slightly peppery flavor make it ideal for fresh salads, pasta dishes, soups, and gourmet pesto. The purple foliage adds visual appeal to dishes while providing a more complex taste than standard green basil. [source]

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Flavored Oils & Vinegars

Culinary

The strong flavor profile and ornamental appeal of Magnus make it excellent for infusing into oils and vinegars for gourmet cooking, gift-giving, or restaurant-quality presentations. [source]

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Herbal Tea & Digestive Aid

Medicinal

Basil leaves can be brewed into a soothing tea that aids digestion and may help reduce bloating and stomach discomfort. Traditional herbalism values basil for its anti-inflammatory and antimicrobial properties. [source]

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Aromatic & Pest Deterrent

Household

Fresh or dried Magnus basil releases a strong fragrance that repels mosquitoes, flies, and other insects when kept in indoor spaces or dried and used in sachets. The essential oils in basil are natural insect deterrents. [source]

🎨

Ornamental Garden Display

Craft

The striking deep purple foliage makes Magnus basil an attractive ornamental plant for containers, herb gardens, and landscape borders. It serves both aesthetic and culinary purposes in garden design. [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 pinching leaves when plant is 6-8 inches tall to encourage bushiness. Pinch off flower buds to prolong the vegetative season and maintain leaf quality. Harvest upper leaves and stems regularly for best growth; never remove more than 1/3 of the plant at once. Harvest in the morning after dew dries for best flavor and fragrance. Leaves are most flavorful just before flowering. Regular harvesting extends the season and prevents early senescence. Cut stems just above a leaf node to encourage branching.

Fun Facts

🌱 Magnus basil is a large-leafed cultivar that can produce leaves 2-3 times larger than standard Genovese basil, making harvesting and preparation faster and more rewarding.
🌱 The purple pigmentation in Magnus comes from anthocyanin compounds, the same antioxidants found in blueberries and red wine, giving it potential additional health benefits beyond traditional green basil.
🌱 Basil was originally domesticated in Central Africa and India over 5,000 years ago, with different cultures developing their own varieties—Magnus represents modern breeding for superior size and flavor for Western culinary traditions.

Gardening Terms

New to gardening? Learn about terms used in this guide:

Annual Cultivar Full Sun True Leaves

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