Basil 'Thai Siam Queen' Seeds

Ocimum basilicum 'Thai Siam Queen' is an improved, premium variety of Thai basil. While standard Thai basil can sometimes get a bit leggy and scruffy, 'Siam Queen' was bred to be compact, bushy, and incredibly beautiful.

It produces huge, dense heads of deep purple flowers that look almost like Chrysanthemums or Celosia. The foliage releases that signature intense aniseed and liquorice aroma, making it a dual-purpose plant: magnificent in the flower border and essential in the kitchen.

Why Your Garden Needs 'Siam Queen'

This is the variety we recommend if you have limited space or grow in containers on a patio. Because it stays neat and bushy, it makes a stunning specimen plant in a terracotta pot. It doesn't flop over like some larger varieties.

Culinary-wise, it is a powerhouse. The leaves are thicker and more tender than standard varieties, holding up perfectly in high-heat cooking like stir-fries and curries. It brings that authentic "street food" flavour to your home cooking.

Understanding the Plant: What is a Tender Annual?

Basil is a Tender Annual.

This means it is strictly a summer visitor. It originates from tropical climates and has zero tolerance for frost or cold, wet soil. You sow it in the warmth of spring, enjoy its vigorous growth throughout the hot months, and let it go when the autumn chills arrive.

Growing Guide: How to Sow and Grow

Like all Thai basils, 'Siam Queen' craves warmth. Don't rush to get it outside!

🌱 Germination:
Sow indoors from March to May. The seeds need warmth (20-25°C) to germinate. Sow them on the surface of moist compost and cover with a fine dusting of vermiculite (they need light to wake up). A heated propagator is ideal to get them started quickly.

Where to Sow:
Start in small pots or modules. Do not plant outside until June when the soil has warmed up. 'Siam Queen' thrives in a greenhouse, polytunnel, or a sunny, sheltered patio where it can soak up the heat.

Care While Growing:
To Flower or Not to Flower? With most basil, we pinch off the flowers to encourage leaves. However, 'Siam Queen' is grown partly for its massive purple blooms. My advice is to harvest the leaves continuously from the side shoots for cooking, but allow the central stem to bloom so you can enjoy the display (and the bees can enjoy the nectar!).

Plant Specifications

Here is a quick reference guide to the key features, helping you decide if this ornamental herb is the right fit for your garden.

My Recommended Garden Companions

'Siam Queen' is beautiful enough to grow in a flower border, not just the veg patch. Here are my top pairings from the shop:

• 🏵️ French Marigolds (Tagetes): The deep orange flowers of Tagetes create a vibrant tropical look when planted next to the purple heads of 'Siam Queen'. They also help deter pests.
• 🟠 Calendula (Pot Marigold): Easy, reliable, and sun-loving. Calendula adds a splash of sunshine next to your basil pots and attracts hoverflies to keep the leaves clean of aphids.

📅 Sowing & Harvesting Calendar

Sow indoors in warmth. Harvest leaves continuously, or let the flowers bloom for a display.

(↔️ Swipe chart to see all months)