Basil Thai Siam Queen
Thai Basil 'Siam Queen' Seeds
Award-winning aromatic beauty with regal purple flower 'crowns'. A sturdy, slow-to-bolt variety with a bold anise-clove punch that stands up perfectly to heat.
If you love Thai Green Curry or spicy stir-fries, standard Italian basil simply won't cut it—the flavour is all wrong and it turns bitter and black the moment it hits heat. You need 'Siam Queen'. This award-winning variety (All-America Selections 1997) offers an intensely aromatic flavour profile with bold notes of aniseed, liquorice, and clove that stand up beautifully to high-temperature cooking. Unlike Genovese basil (which must be added at the last second), Thai Basil can be stirred into bubbling curries at the start to infuse the coconut milk base with that authentic Southeast Asian complexity, then tossed in fresh at the end for a final aromatic punch!
But 'Siam Queen' isn't just about culinary excellence—it's an architectural beauty with genuine ornamental wow-factor! This improved cultivar grows into a sturdy, compact, bushy mound (50-60cm tall) with glossy olive-green leaves sprouting from dramatic purple-red stems. Late in the season, it produces absolutely spectacular dense spikes of deep lavender-purple flowers (8-12cm tall!) that rise above the foliage like regal crowns. The flower display is truly breath taking—pollinators go absolutely wild for them! What makes 'Siam Queen' genuinely special is its slow-to-bolt nature: unlike most basils (where flowering ruins the flavour), 'Siam Queen' retains its delicious sweet-spicy anise flavour even when blooming, so you can enjoy BOTH the stunning ornamental display AND continue harvesting leaves throughout summer and into autumn. Spectacular in a pot on a sunny patio, productive enough for serious cooking, and beautiful enough to win horticultural awards!
Read More
🌿 Understanding the Plant
Ocimum basilicum var. thyrsiflora 'Siam Queen' is a robust Tender Annual. Winner of the prestigious All-America Selections Award, it is horticultural royalty, specifically bred for its extra-large leaves and spectacular ornamental presence. Biologically, it is a heat-loving tropical species, requiring consistent warmth and full sun to develop its rich essential oils and dramatic purple pigments.
The "Horapa" Profile: Known in Thailand as Bai Horapa, this variety possesses a higher concentration of eugenol (clove oil) and estragole (aniseed/liquorice) than standard Italian basil. This chemical profile gives it the structural integrity to withstand high-temperature stir-frying and simmering without the flavour compounds breaking down into bitterness.
Ornamental Crown: The defining feature of 'Siam Queen' is its unique flowering habit. While standard basils produce small, sparse flower spikes, this variety develops dense, terminal clusters of deep lavender flowers (thyrses). This "crown" not only serves a significant aesthetic purpose but is also an exceptional resource for British bees and hoverflies in late summer.
🌱 Growing Guide
Thai Basil seeds require light and significant warmth to break dormancy and ensure uniform germination.
How to Sow:
Sow indoors from March to May. Surface sow the seeds onto moist, high-quality seed compost and do not cover them; basil seeds are photoblastic and require light to trigger germination. Provide a consistent temperature of 20-25°C—a heated propagator or warm airing cupboard is ideal. Germination is typically rapid, occurring within 5-10 days.
Where to Plant:
They demand full sun and thrive in rich, fertile, and well-drained soil. 'Siam Queen' is particularly well-suited to large decorative pots on a sun-drenched patio or within a greenhouse. Space plants 25-30cm apart. Crucial: Only plant out in late June once night time temperatures consistently remain above 10-12°C, as cold winds will damage the succulent foliage.
The "Pinching" Secret:
To maintain the signature compact, bushy habit, you must pinch out the growing tips once the seedlings reach 15cm in height. This signals the plant to divert energy into lateral branching, resulting in nearly double the leaf yield. Unlike other basils, the flavour remains sweet even as the purple flower spikes emerge, allowing for a combined ornamental and culinary harvest.
📋 Plant Specifications
| Botanical Name | Ocimum basilicum var. thyrsiflora |
| Common Name | Thai Basil / Siam Queen |
| Plant Type | Tender Annual |
| Hardiness | H1c (Frost sensitive) |
| Light Requirements | Full Sun ☀️ |
| Height | 50cm - 60cm (Bushy & Mounded) |
| Spread | 40cm |
| Spacing | Plant 25cm apart |
| Flowering Period | July to October |
| Perfect For | 🍜 Authentic Thai & Asian Cooking 🏺 High-Impact Ornamental Containers 🐝 Late Summer Pollinator Support 🌿 Fragrant Edible Landscapes |
| Seeds per Packet | Approximately 100 seeds |
🤝 Beautiful Garden Combinations
The glossy green leaves and purple crowns of 'Siam Queen' work spectacularly with available partners from our range:
- 🧡 Calendula 'Neon': The Vibrant Potager. A high-energy, professional-looking combination. The intense electric-orange of the Calendula provides a stunning contrast to the deep purple stems and flowers of the Thai Basil. Both are edible and attract beneficial pollinators to your vegetable patch.
- 🌿 Borage (Starflower): The Bee Magnet Team. For an edible landscape focused on biodiversity, pair 'Siam Queen' with Borage. The sky-blue starflowers complement the lavender-purple basil spikes perfectly, creating a long-season buffet that is irresistible to British honeybees and butterflies.
📅 Sowing & Flowering Calendar
Sow indoors in spring for a summer-long harvest of spicy anise leaves and spectacular purple crowns that will last until the first frosts.
✨ Gourmet Crown Tip
The lavender-purple flower spikes of 'Siam Queen' are 100% edible and possess an even more intense anise-clove flavour than the leaves. Use them as a regal, aromatic garnish for curries or freeze the individual florets into ice cubes for botanical summer cocktails.
🏆 Robust Garden Stamina
Known for its stamina and ability to thrive in warm microclimates, Ocimum basilicum 'Siam Queen' is an essential choice for those wanting to create a romantic, low-maintenance garden that provides non-stop spicy leaves and architectural purple crowns.
📖 Want more detailed growing advice?
View our Complete Growing Guide for Herbs →
Original: $2.61
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$0.78
Description
Thai Basil 'Siam Queen' Seeds
Award-winning aromatic beauty with regal purple flower 'crowns'. A sturdy, slow-to-bolt variety with a bold anise-clove punch that stands up perfectly to heat.
If you love Thai Green Curry or spicy stir-fries, standard Italian basil simply won't cut it—the flavour is all wrong and it turns bitter and black the moment it hits heat. You need 'Siam Queen'. This award-winning variety (All-America Selections 1997) offers an intensely aromatic flavour profile with bold notes of aniseed, liquorice, and clove that stand up beautifully to high-temperature cooking. Unlike Genovese basil (which must be added at the last second), Thai Basil can be stirred into bubbling curries at the start to infuse the coconut milk base with that authentic Southeast Asian complexity, then tossed in fresh at the end for a final aromatic punch!
But 'Siam Queen' isn't just about culinary excellence—it's an architectural beauty with genuine ornamental wow-factor! This improved cultivar grows into a sturdy, compact, bushy mound (50-60cm tall) with glossy olive-green leaves sprouting from dramatic purple-red stems. Late in the season, it produces absolutely spectacular dense spikes of deep lavender-purple flowers (8-12cm tall!) that rise above the foliage like regal crowns. The flower display is truly breath taking—pollinators go absolutely wild for them! What makes 'Siam Queen' genuinely special is its slow-to-bolt nature: unlike most basils (where flowering ruins the flavour), 'Siam Queen' retains its delicious sweet-spicy anise flavour even when blooming, so you can enjoy BOTH the stunning ornamental display AND continue harvesting leaves throughout summer and into autumn. Spectacular in a pot on a sunny patio, productive enough for serious cooking, and beautiful enough to win horticultural awards!
Read More
🌿 Understanding the Plant
Ocimum basilicum var. thyrsiflora 'Siam Queen' is a robust Tender Annual. Winner of the prestigious All-America Selections Award, it is horticultural royalty, specifically bred for its extra-large leaves and spectacular ornamental presence. Biologically, it is a heat-loving tropical species, requiring consistent warmth and full sun to develop its rich essential oils and dramatic purple pigments.
The "Horapa" Profile: Known in Thailand as Bai Horapa, this variety possesses a higher concentration of eugenol (clove oil) and estragole (aniseed/liquorice) than standard Italian basil. This chemical profile gives it the structural integrity to withstand high-temperature stir-frying and simmering without the flavour compounds breaking down into bitterness.
Ornamental Crown: The defining feature of 'Siam Queen' is its unique flowering habit. While standard basils produce small, sparse flower spikes, this variety develops dense, terminal clusters of deep lavender flowers (thyrses). This "crown" not only serves a significant aesthetic purpose but is also an exceptional resource for British bees and hoverflies in late summer.
🌱 Growing Guide
Thai Basil seeds require light and significant warmth to break dormancy and ensure uniform germination.
How to Sow:
Sow indoors from March to May. Surface sow the seeds onto moist, high-quality seed compost and do not cover them; basil seeds are photoblastic and require light to trigger germination. Provide a consistent temperature of 20-25°C—a heated propagator or warm airing cupboard is ideal. Germination is typically rapid, occurring within 5-10 days.
Where to Plant:
They demand full sun and thrive in rich, fertile, and well-drained soil. 'Siam Queen' is particularly well-suited to large decorative pots on a sun-drenched patio or within a greenhouse. Space plants 25-30cm apart. Crucial: Only plant out in late June once night time temperatures consistently remain above 10-12°C, as cold winds will damage the succulent foliage.
The "Pinching" Secret:
To maintain the signature compact, bushy habit, you must pinch out the growing tips once the seedlings reach 15cm in height. This signals the plant to divert energy into lateral branching, resulting in nearly double the leaf yield. Unlike other basils, the flavour remains sweet even as the purple flower spikes emerge, allowing for a combined ornamental and culinary harvest.
📋 Plant Specifications
| Botanical Name | Ocimum basilicum var. thyrsiflora |
| Common Name | Thai Basil / Siam Queen |
| Plant Type | Tender Annual |
| Hardiness | H1c (Frost sensitive) |
| Light Requirements | Full Sun ☀️ |
| Height | 50cm - 60cm (Bushy & Mounded) |
| Spread | 40cm |
| Spacing | Plant 25cm apart |
| Flowering Period | July to October |
| Perfect For | 🍜 Authentic Thai & Asian Cooking 🏺 High-Impact Ornamental Containers 🐝 Late Summer Pollinator Support 🌿 Fragrant Edible Landscapes |
| Seeds per Packet | Approximately 100 seeds |
🤝 Beautiful Garden Combinations
The glossy green leaves and purple crowns of 'Siam Queen' work spectacularly with available partners from our range:
- 🧡 Calendula 'Neon': The Vibrant Potager. A high-energy, professional-looking combination. The intense electric-orange of the Calendula provides a stunning contrast to the deep purple stems and flowers of the Thai Basil. Both are edible and attract beneficial pollinators to your vegetable patch.
- 🌿 Borage (Starflower): The Bee Magnet Team. For an edible landscape focused on biodiversity, pair 'Siam Queen' with Borage. The sky-blue starflowers complement the lavender-purple basil spikes perfectly, creating a long-season buffet that is irresistible to British honeybees and butterflies.
📅 Sowing & Flowering Calendar
Sow indoors in spring for a summer-long harvest of spicy anise leaves and spectacular purple crowns that will last until the first frosts.
✨ Gourmet Crown Tip
The lavender-purple flower spikes of 'Siam Queen' are 100% edible and possess an even more intense anise-clove flavour than the leaves. Use them as a regal, aromatic garnish for curries or freeze the individual florets into ice cubes for botanical summer cocktails.
🏆 Robust Garden Stamina
Known for its stamina and ability to thrive in warm microclimates, Ocimum basilicum 'Siam Queen' is an essential choice for those wanting to create a romantic, low-maintenance garden that provides non-stop spicy leaves and architectural purple crowns.
📖 Want more detailed growing advice?
View our Complete Growing Guide for Herbs →
