How to Grow Bangkok Giant

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Bangkok Giant

Ocimum basilicum var. basilicum 'Bangkok Giant'

herb

Bangkok Giant is a large-leaved Thai basil cultivar prized for its distinctive anise-like flavor and impressive size. This ornamental and culinary herb produces abundant, deep green foliage and purple flowers, thriving in warm climates. It's a staple in Southeast Asian cuisine and grows vigorously in containers or garden beds.

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Example Bangkok Giant timeline · Pittsburgh, PA (Zone 6b)

  1. Plant Bangkok Giant

    Around Apr 17

    Near Pittsburgh's average last spring frost.

  2. Tend & protect

    Late spring–summer

    Watering, feeding, and pest-watch reminders.

  3. Harvest Bangkok Giant

    Around Jun 16

    ≈ 60 days after planting

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

Growing Conditions

☀️
Sun: Full sun, 6-8 hours daily (prefers 8+ hours)
💧
Water: Keep soil consistently moist but not waterlogged; water regularly, especially in hot weather. Reduce watering in fall/winter. Tolerates drier conditions better than sweet basil once established.
📏
Spacing: 12 inches
📅
Days to maturity: 60-90 days
🌱
Planting depth: 0.25 inches (surface sow or barely cover seeds)

Soil

Type: Well-draining loamy soil with organic matter
pH: 6.0-7.0
Amendments:
Compost Peat moss or coconut coir Perlite for drainage Balanced organic fertilizer

Growing Zones

Find your zone →

Zones 10-11; annual in zones 3-9 when grown in summer

10a 10b 11a 11b

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Growth Stages

1

Germination & Seedling

10-14 days to emergence, 2-3 weeks to true leaves

Tiny seedlings emerge with cotyledons (seed leaves); true leaves develop within 1-2 weeks. Plants are delicate and light green.

Keep soil warm (75-80°F) and consistently moist. Provide bright light; use grow lights if indoors. Thin seedlings to strongest specimens.

2

Vegetative Growth

4-6 weeks

Plant develops multiple sets of true leaves and expands rapidly. Stems thicken and foliage becomes dense and full. Characteristic large, deep green leaves appear.

Pinch growing tips regularly to encourage bushiness. Water consistently and feed with balanced fertilizer every 2-3 weeks. Maintain warm temperatures (70-85°F).

3

Pre-flowering & Flowering

Begins around 6-8 weeks; continues through season

Plant produces terminal flower spikes with small purple or lavender flowers. Flowering indicates maturity and can slow leaf production if allowed to proceed heavily.

Pinch off flower buds to extend leafy harvest period and promote bushier growth. If allowing some flowers for ornamental value, deadhead occasionally. Continue regular harvesting.

4

Peak Production & Maintenance

6-12 weeks depending on climate

Plant reaches full size (2-3 feet) with abundant harvestable foliage. Continues flowering and leaf production. Growth is vigorous and dense.

Harvest regularly by pinching off top 4-6 inches of stems; this maintains bushiness and delays heavy flowering. Continue consistent watering and feeding. Monitor for pests.

5

Senescence/End of Season

Variable; typically 2-3 months before first frost in temperate zones

In cooler climates or as daylight decreases, growth slows. Heavy flowering occurs; foliage may become sparse at base. Plant may decline in cold weather.

In zones 3-9, harvest heavily before first frost or move containers indoors to frost-free location. In zones 10-11, plant can persist year-round; light pruning may rejuvenate older plants.

Companion Planting

Plan your garden →

Plant with:

Avoid planting near:

Rue Fennel Cucumber Brassicas (cabbage, broccoli)

Common Pests

  • Hand-pick in early morning; use neem oil spray; encourage beneficial insects like parasitic wasps

  • Increase humidity by misting; spray with neem oil or insecticidal soap; prune heavily infested areas

  • Use yellow sticky traps; spray with neem oil or insecticidal soap; remove heavily affected leaves

  • Ensure excellent drainage; avoid overhead watering; remove infected plants; rotate plantings; use disease-resistant seed if available

  • Improve drainage and air circulation; avoid overwatering; use sterile potting mix for containers; drench soil with beneficial fungi (mycorrhizae)

  • and

    Hand-pick at night; create barriers with diatomaceous earth; trap with beer-filled containers; encourage natural predators

Uses

🍳

Thai & Southeast Asian Cuisine

Culinary

Bangkok Giant basil is essential in Thai cooking, used in curries, stir-fries, pad krapow (Thai basil chicken), and soups. Its anise-like, licorice flavor is more complex and peppery than sweet basil. Leaves are typically added at the end of cooking to preserve flavor. [source]

🍳

Fresh & Aromatic Flavoring

Culinary

Fresh leaves can be used in drinks, desserts, and as a garnish for fruit or Asian-fusion dishes. The purple flowers are edible and ornamental, adding spice to salads and drinks. [source]

💊

Traditional Herbal Remedy

Medicinal

In traditional Thai and Ayurvedic medicine, Thai basil is used to support digestion, reduce inflammation, and soothe respiratory discomfort. Tea made from leaves may aid digestion and provide anti-inflammatory benefits. [source]

🏠

Aromatic & Insect Repellent

Household

Fresh or dried leaves can be dried and used in potpourri for their strong, pleasant aroma. The plant's natural oils may help repel mosquitoes and other insects in the garden. [source]

🦋

Pollinator Support

Wildlife

Bangkok Giant's purple flowers attract bees, butterflies, and other beneficial insects, supporting pollinator populations in gardens. [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 sets of true leaves (4-6 weeks). Pinch off top 4-6 inches of stems regularly—this encourages bushier growth and delays flowering. Harvest in the morning after dew dries for peak flavor and aroma. Remove flower buds as they appear to extend the harvest of flavorful leaves. In zones 3-9, harvest heavily before first frost. Leaves can be used fresh or frozen in ice cube trays with a bit of water for later use.

Fun Facts

  • 🌱 Bangkok Giant is significantly larger than sweet basil, with leaves up to 2 inches long and plants reaching 2-3 feet tall, making it a striking ornamental as well as a culinary herb.
  • 🌱 In Thai culture, basil is believed to offer spiritual protection, and different basil varieties (sweet, purple, and Thai) are used in different culinary and ceremonial contexts.
  • 🌱 The distinctive anise/licorice flavor in Thai basil comes from estragole and linalool compounds, which differ from the eugenol profile found in sweet Italian basil.

Gardening Terms

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

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