Siam Queen Thai Basil (Ocimum basilicum var. thyrsiflora) is a striking, aromatic basil variety with tall upright growth, dark purple stems, and pink-lavender flower clusters. This non-GMO annual thrives in warm climates and excels in sunny borders, herb garden designs, container plantings, and raised beds. Its flower spikes attract bees and other beneficial pollinators, making it a standout ornamental herb for summer landscapes.
Features
- Tall, upright basil with purple stems and flower spikes
- Non-GMO Ocimum basilicum var. thyrsiflora
- Excellent for containers, borders, and raised beds
- Highly aromatic foliage for sensory and ornamental gardens
- Flower clusters attract bees and pollinators
- Strong, vigorous summer grower
Specifications
- Common Name: Siam Queen Thai Basil
- Scientific Name: Ocimum basilicum var. thyrsiflora
- Plant Type: Annual
- USDA Zones: 4–11 (warm-season annual)
- Season: Late spring through summer
- Height: 16–30 inches
- Foliage: Bright green aromatic leaves, purple stems
- Bloom Color: Pink-lavender flowers
- Heirloom: Yes
- GMO Status: Non-GMO
- Organic: Not certified organic
- Light Requirements: Full sun
- Soil Preference: Rich, well-drained garden soil
- Water Needs: Moderate; consistent moisture
- Growth Rate: Fast
- Days to Maturity: 60–75 days
- Heat Tolerance: Excellent
- Cold Tolerance: Poor; frost sensitive
- Plant Spacing: 12–14 inches
- Seed Longevity: 3–5 years stored cool & dry
Planting Guide
- Sowing Method: Start indoors or direct sow after frost.
- Seed Preparation: No pre-treatment required.
- When to Plant:
- Indoors: 4–6 weeks before final frost
- Outdoors: After soil warms and frost is gone
- Sowing Depth: 1/8 inch; lightly press and cover.
- Germination Time: 7–14 days with warmth.
- Light Requirements: Full sun for upright, vigorous growth.
- Soil Conditions: Use loose, nutrient-rich, well-draining soil.
- Watering: Maintain even moisture; avoid waterlogging.
- Maintenance:
- Pinch tips for branching and denser foliage
- Remove early flower spikes for extended leaf growth
- Avoid overwatering in containers
