How to Grow Vietnamese Basil

Vietnamese Basil

Ocimum basilicum var. thyrsiflorum

herb

Vietnamese basil is a tropical basil variety with narrow, serrated leaves and a distinctive anise-licorice flavor profile. It features purple-tinged stems and decorative purple flower spikes, making it both ornamental and culinary. This heat-loving herb is essential in Southeast Asian cuisine, particularly Vietnamese and Thai cooking.

Growing Conditions

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Sun: Full sun, 6-8 hours daily; tolerates partial shade in hot climates

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Water: Keep soil consistently moist but not waterlogged; water deeply when top inch is dry. Prefers regular moisture; drought stress reduces leaf quality

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Spacing: 12 inches

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Days to maturity: 60-90 days

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Planting depth: 1/4 inch; barely cover seeds or start from transplants

Soil

Type: Well-draining loamy soil with organic matter

pH: 6.0-7.0

Amendments:

Compost Aged manure Perlite or sand for drainage

Growing Zones

Find your zone →

Thrives in zones 10-11; grow as an annual in cooler zones or indoors

10b 11a 11b

Growth Stages

Seedling

2-3 weeks

Tiny rounded cotyledons emerge; true leaves develop within 1-2 weeks with characteristic narrow, serrated edges

Keep soil warm (70-85°F); maintain consistent moisture; provide bright indirect light; thin seedlings to prevent crowding

Vegetative Growth

3-5 weeks

Plant develops multiple stems with narrow, lance-shaped leaves; purple coloring develops in stems and leaf veins; no flowers yet

Pinch growing tips regularly to encourage bushier growth; provide 6-8 hours of direct sunlight; water consistently; fertilize biweekly with balanced fertilizer

Flowering

4-8 weeks (ongoing after first buds form)

Tall flower spikes with dense purple flowers develop; leaves may become slightly thinner and more aromatic

Pinch off flower buds to extend leaf production if harvesting for culinary use; allow some flowers to bloom for ornamental interest and pollinator support

Seed Production

3-4 weeks

Flowers mature into seed pods; seeds develop within tiny capsules; plant may show signs of senescence

Allow flowers to mature fully if saving seeds; dry seed pods on the plant or harvest before full drying and finish indoors

Harvest & Maintenance

Ongoing, 2-4 months or until frost

Plant is actively producing harvestable leaves; with proper pinching, continues producing for months in warm conditions

Harvest young leaves regularly for best flavor; remove flower buds to redirect energy to foliage; continue regular watering and feeding

Companion Planting

Plan your garden →

Plant with:

Tomato Pepper Eggplant Cilantro Parsley Garlic Onion Marigold

Avoid planting near:

Rue Sage Fennel

Common Pests

Hand-pick in early morning; use neem oil spray; encourage beneficial insects
Increase humidity; spray with water to dislodge; use insecticidal soap or neem oil
Strong water spray to remove; insecticidal soap; neem oil; attract ladybugs
Yellow sticky traps; neem oil; insecticidal soap; improve air circulation
Remove infected plants; improve drainage; avoid overhead watering; sterilize tools

Uses

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Southeast Asian Cooking

Culinary

Vietnamese basil is a cornerstone ingredient in pho, bánh mì, spring rolls, and Vietnamese curries. Its distinctive anise-licorice flavor elevates both cooked and fresh dishes, particularly in Vietnamese and Thai cuisines. [source]

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Fresh Garnish & Salads

Culinary

Use whole leaves as a vibrant garnish or tear into Asian noodle salads, stir-fries, and seafood dishes. The decorative purple flowers are also edible and add visual appeal. [source]

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Digestive & Anti-inflammatory Support

Medicinal

Traditional Vietnamese medicine uses basil for digestive health and to reduce inflammation. The volatile oils, including estragole and methyl cinnamate, support digestive function. [source]

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Culinary Oil & Infusions

Household

Infuse fresh leaves in vinegars, oils, or alcohol to create flavorful condiments and cooking ingredients. The strong aromatic compounds create distinctive preserved flavorings. [source]

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Pollinator Attraction

Wildlife

Purple flower spikes attract bees, butterflies, and hoverflies, supporting garden pollinator populations. Allow some flowers to bloom to benefit beneficial insects. [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 leaves when plant has 6-8 true leaves; pinch off top 1/4 inch of stems for bushier growth; harvest in morning after dew dries for best flavor and aroma. Regular harvesting (2-3 times weekly) promotes continued leaf production. Remove flower buds as they form to extend the vegetative stage. Use leaves fresh or dry within a few hours of harvest for maximum flavor.

Fun Facts

🌱 Vietnamese basil is distinct from sweet basil and Thai basil, with a unique anise flavor that comes from different volatile oil compositions including higher estragole content.
🌱 The purple flower spikes are a distinctive ornamental feature of this variety and are fully edible, with a flavor similar to the leaves.
🌱 Vietnamese basil is exceptionally heat-loving and actually grows better in hot, humid conditions than most other basil varieties, thriving in tropical climates where sweet basil struggles.

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