How to Grow Italian Large Leaf Basil
Wikimedia Commons
Italian Large Leaf Basil
Ocimum basilicum var. basilicum
herbItalian Large Leaf basil is a culinary herb prized for its large, tender leaves and robust flavor. It's a warm-season annual that grows vigorously in warm conditions and is essential for Italian cooking, particularly pesto. The plant reaches 12-24 inches tall with broad, glossy green foliage.
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Example Italian Large Leaf Basil timeline · Pittsburgh, PA (Zone 6b)
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Plant Italian Large Leaf 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 Italian Large Leaf Basil
Around Jun 16≈ 60 days after planting
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Growing Conditions
Soil
Growing Zones
Find your zone →Thrives in zones 3-11; prefers warm conditions (70-85°F) and dies at frost
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Germination & Seedling
2-3 weeksSeeds sprout in 5-10 days at warm temperatures (70-75°F). First leaves emerge as small, oval cotyledons, followed by true leaves.
Keep soil consistently warm and moist. Provide bright light to prevent legginess. Thin seedlings to proper spacing once true leaves appear.
Vegetative Growth
3-4 weeksPlant develops multiple stems and increasingly larger, broader leaves. Foliage becomes dense and bushy. Leaves darken and become more flavorful.
Pinch out growing tips regularly to encourage branching and fuller form. Water consistently and provide full sun. Feed with balanced fertilizer every 3-4 weeks.
Pre-flowering
1-2 weeksPlant reaches mature size with large, fully-sized leaves. Small flower buds begin forming at stem tips, signaling impending reproductive phase.
Continue pinching flower buds and leaf tips to delay flowering and encourage leaf production. Maintain consistent watering and warmth.
Flowering
2-4 weeks (until frost or plant senescence)Small white, pink, or purple flowers form in terminal spikes. Leaves become smaller and less flavorful as energy shifts to seed production.
Deadhead flowers immediately to prolong leaf production. If flowering occurs, harvest leaves aggressively before quality declines.
Decline
Until first frost or plant deathPlant weakens, produces smaller leaves, and foliage quality diminishes. In cool climates, frost kills the plant entirely.
Replace with fresh seedlings for continuous harvest. Collect seeds if desired before frost.
Common Pests
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Spray with strong water stream; use insecticidal soap; encourage beneficial insects like ladybugs
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Increase humidity; spray with water mist; use neem oil; ensure adequate moisture
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Hand-pick in early morning; use row covers; apply neem oil
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Use yellow sticky traps; spray neem oil; encourage parasitic wasps
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Improve air circulation; avoid overhead watering; apply sulfur dust or baking soda spray; remove affected leaves
Uses
Pesto & Fresh Cooking
CulinaryItalian Large Leaf basil is the traditional choice for pesto, combining with pine nuts, garlic, Parmesan, and olive oil. The large leaves are ideal for wrapping, tearing for salads, and fresh pasta dishes. [source]
Italian Cuisine
CulinaryA cornerstone of Italian cooking, especially in Caprese salad (with tomato and mozzarella), pasta sauces, and garlic bread. The robust flavor stands up to cooking and marinades. [source]
Anti-inflammatory & Digestive Support
MedicinalBasil contains compounds like eugenol and linalool with anti-inflammatory properties. Traditionally brewed as tea to aid digestion and reduce bloating. [source]
Natural Air Freshener
HouseholdFresh basil naturally perfumes indoor spaces and has mild antimicrobial properties. Dried leaves retain aroma and can be used in potpourri or sachets. [source]
Pollinator Attraction
WildlifeWhen allowed to flower, basil's small white blooms attract bees and other beneficial pollinators to the garden, supporting ecosystem health. [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 6-8 true leaves (approximately 3-4 weeks after planting). Pinch off leaves from the top to encourage bushiness. For maximum flavor, harvest in early morning after dew dries. Remove flower buds regularly to extend leaf production. Continuous harvesting promotes more growth—never remove more than one-third of the plant at once. Regular harvesting delays flowering and maintains tender, flavorful leaves.
Fun Facts
- 🌱 Italian Large Leaf basil is heat-loving and actually grows better when temperatures stay above 70°F—it's one of the few herbs that genuinely thrives in summer heat.
- 🌱 The larger leaf size of this variety (compared to sweet basil) makes it ideal for harvesting whole leaves for wrapping or presentation, and is why it's preferred by chefs for visual appeal.
- 🌱 Basil's essential oils include linalool and estragole, which give it its characteristic sweet-spicy aroma and are the same compounds found in anise and some flowers.
Gardening Terms
New to gardening? Learn about terms used in this guide:
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