Growing Herbs From Seed — How to Get Good Germination

Growing herbs from seed is more economical than buying plants and gives you access to a much wider range of varieties. Most culinary herbs germinate readily with the right conditions, but each has specific requirements — the right temperature, moisture level, and sowing method — that make the difference between a successful germination and a tray of nothing happening.

Easy Herbs to Grow From Seed

Some herbs are remarkably easy to grow from seed and are ideal starting points. Basil, coriander, dill, chives, fennel, and borage all germinate within one to two weeks at the right temperature and require no special treatment. Sow basil indoors from March to May at 18–22°C; chives and dill can be sown outdoors from April in a sunny spot. Parsley germinates more slowly (two to four weeks) but is not difficult — it simply needs patience and consistent moisture. These easy herbs build confidence before you move on to slower species.

Herbs That Are Slower or Trickier

Thyme, sage, rosemary, and lavender all germinate more slowly and less predictably from seed. Rosemary seed in particular has notoriously low germination rates — sometimes as low as 30–40% even from fresh seed. For these herbs, sow more seed than you think you need (a pinch of thyme seed rather than a few seeds), and expect some failures. Lavender seed benefits from cold stratification: mix the seed with damp compost in a sealed bag and refrigerate for two to four weeks before sowing, which mimics the cold period the seed needs in nature to break dormancy.

Key Germination Conditions

Most herbs need warmth, moisture, and light to germinate. The minimum soil temperature for most is around 15–18°C; basil and coriander prefer 20°C or above. Sow in a good-quality seed compost rather than standard potting mix — seed compost is fine-textured and low in nutrients, which is ideal for germination. Cover seeds lightly (most herb seeds need only a thin covering, or no covering if very fine) and keep moist but not waterlogged. A clear propagator lid or stretched cling film over the tray retains humidity and warmth, speeding germination significantly.

Direct Sowing vs Indoor Sowing

Herbs that resent transplanting — coriander, dill, fennel — should be sown directly where they are to grow. Sow in a prepared bed or large container and thin to the appropriate spacing once seedlings are established. Most other herbs can be started indoors in modules or trays and transplanted once they are large enough to handle, but handle roots gently. Basil is best started in a warm spot indoors and transplanted after the last frost date; it suffers badly if the roots are disturbed when the plant is small.

Aftercare for Herb Seedlings

Once herb seeds germinate, remove the propagator lid gradually over a few days to acclimatise seedlings to normal air. Move to a bright windowsill or under grow lights immediately — seedlings deprived of light become pale and leggy within days. Water carefully at the base of the seedling rather than from above, which can cause damping off (a fungal disease that kills seedlings at soil level). Begin feeding with a very dilute liquid feed once seedlings have two or three true leaves. Prick out into individual modules once large enough to handle and grow on until ready to plant out.