Thai Basil

Thai Basil: variety and characteristics

Thai Basil (Ocimum basilicum) is an annual herb of the Mint family (Lamiaceae). This exotic basil comes from Thailand and Vietnam. Its flavour is something between aniseed, clove and basil, and it is not only used in many Asian dishes but also makes an excellent tea and is an interesting medicinal plant.

Plants reach a height of 30-45 cm. The flowers appear at the tips of the leaves and are a deep burgundy in colour. It can also be grown in pots.

The plants will produce stems, leaves and flowers, all within one growing season, and can be harvested after 80 days.

If fresh seeds are collected, new plants can be established in the following growing season.

Basil is the king of aromatic herbs — for tomato salad, pesto, pasta and pizza. It grows easily in the garden, in a pot and on a windowsill.

Key features

• Measured germination rate of the batch: 80%
• Seeds per packet: 96–131 pcs (0.2 g)
• Seed origin: India
• Sowing: March and April; transplants or direct
• Flowering: June – September
• Harvest: June – September
• Position: sunny spot

When to sow Thai Basil

Thai Basil seeds are sown in March and April. The plants flower from June to September. The crop is harvested from June to September. The months are a guide for a temperate climate — in warmer areas sow 1–2 weeks earlier, in cooler or upland areas, later.

How to sow and grow Thai Basil

• Sowing method: seedlings or direct
• Depth: 0.3–0.5 cm
• Spacing: 20–30 cm
• Germination: 5–10 days at 20–25 °C
• Position: sunny spot

To sow the seeds outdoors, it is best to wait until mid-March for direct sowing, when temperatures rise. Basil seeds need warmth to germinate, ideally around 21°C. This can easily be achieved on a sunny windowsill indoors. Basil can also be grown indoors all year round, especially if you have a sunny window or full-spectrum lights. It does great in containers; just make sure you add some compost or another nutrient-rich amendment to your potting mix. Once germinated, encourage strong seedlings by giving them plenty of sun and moisture. Do not overwater: basil seedlings are very prone to damping off. A greenhouse is the ideal place for your basil plants, just make sure you water them often to prevent them from flowering prematurely.

Sow in warm soil — below 12 °C basil stops growing. Pinch out the tips so it branches, and remove flowers for more leaves.

Harvest and use

Pick the leaves before flowering — the aroma is strongest then. Cut above a pair of leaves so that new shoots form.

Frequently asked questions

When should Thai Basil be sown?

The recommended sowing months are March and April. Sowing method: seedlings or direct.

How many seeds are in the packet?

The packet contains 96–131 seeds, pack size 0.2 g.

What is the germination rate of the seeds?

The measured germination rate of this batch is 80%. The test was carried out under controlled laboratory conditions; in the field, emergence depends on soil, temperature and moisture.

Can basil be grown on a windowsill?

Yes — on a sunny window, in a pot with drainage, with regular but moderate watering.

Why does basil turn black?

From cold below 10 °C or from overwatering. Only take it outside after mid-May.