Basil Dark Opal

Basil Dark Opal — variety description

Basil Dark Opal (Ocimum basilicum) is an annual herb of the Mint family (Lamiaceae). The stunning violet-purple leaves and pink flowers make this variety ideal for flower beds and pots.

The flavour of basil is ideal combined with tomatoes, and the dark leaves colour and flavour homemade bottles of vinegar.

Basil is great as a herbal tea for stomach complaints.

Pick the young leaves regularly to extend the harvest.

A strongly aromatic plant with a high content of eugenol and rosmarinic acid.

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: 85%
• Pack size: 0.4 g
• Seed origin: Germany
• Sowing: March and April; transplants or direct
• Flowering: June – September
• Harvest: June – September
• Position: sunny spot

When to sow Basil Dark Opal

Basil Dark Opal 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 Basil Dark Opal

• 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

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 Basil Dark Opal be sown?

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

What is the germination rate of the seeds?

The measured germination rate of this batch is 85%. 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.