Starting herbs from seed is cheap, satisfying, and the only way to grow some herbs in the varieties you want. A packet of basil seed costs little and gives you dozens of plants, while a single bought basil plant costs as much as the packet. But herb seed is not all the same: some herbs germinate in days, some take weeks, some need light to germinate, and some are so slow or unreliable from seed that you are better off buying a plant.
This guide covers which herbs to start from seed, which to buy as plants, how to sow, and how to care for seedlings until they are ready to plant out. Use our seed starting calculator to work out sowing dates, and check your local extension service for the sowing dates that fit your area.
Which herbs to grow from seed, and which to buy
Easy from seed are basil, dill, cilantro, parsley and chives. Basil germinates quickly in warmth and grows fast. Dill and cilantro germinate readily but dislike transplanting, so sow them where they are to grow. Parsley is slow — it can take three weeks or more to germinate — but it is reliable if you are patient. Chives germinate steadily and grow into a clump that lasts for years. Chamomile and lemongrass can be grown from seed, though lemongrass is often easier from a bought plant.
Slow or unreliable from seed are rosemary, thyme, sage and lavender. Rosemary seed germinates slowly and unevenly, and seed-grown rosemary may not have the flavour or habit of the parent plant. Thyme seed is tiny and slow, and lavender seed needs a cold period before it will germinate. For these herbs, buy a small plant in your first year, or take cuttings from a friend's plant — both are faster and more reliable than seed. Mint is almost never grown from seed, because seed-grown mint is variable and often poor; grow it from a cutting or a bought plant, in its own pot.
Sowing indoors: trays, compost and depth
Sow tender herbs such as basil indoors a few weeks before the last frost, so they are ready to plant out when the weather warms up. Use clean trays or pots, fresh seed compost, and sow thinly — crowded seedlings grow weak and are prone to damping off. The depth rule is simple: sow at about twice the width of the seed, and no deeper. Tiny seeds such as thyme and chamomile need light to germinate, so press them onto the surface of the compost and do not cover them at all. Larger seeds such as parsley and dill should be covered lightly.
Water gently, from below or with a fine rose, so the seeds are not washed away or buried. Cover the tray with a clear lid or a plastic bag to hold in moisture, and remove it as soon as the seedlings appear, so they get light and air. Label every tray with the herb and the date — seedlings all look alike when they first appear, and an unlabelled tray is a mystery you will regret. Our seed starting calculator can help you work out when to sow each herb for your last frost date.
Germination: warmth, light and patience
Most herb seeds germinate best in warmth. Basil wants warm compost — a warm windowsill or a heated propagator — and it will germinate in a week or so in warmth, but sulk for weeks in a cold room. Parsley is the classic slow germinator: it can take two to three weeks, and soaking the seed in warm water overnight before sowing can speed it up. Dill and cilantro germinate in one to two weeks in cool to warm soil. Rosemary and lavender can take three to four weeks, and their germination is often patchy, which is another reason to buy plants instead.
Give seedlings light as soon as they appear. A seedling on a dark shelf grows tall, pale and weak, reaching for the light, and it will never recover its strength. A sunny windowsill is good, and a grow light is better in winter — our grow light calculator can help you work out what you need. Turn the trays every few days so the seedlings grow straight. And be patient with slow herbs: a parsley tray that shows nothing for two weeks is normal, not a failure — keep the compost moist and wait.
Sowing direct: dill, cilantro and chives
Some herbs are best sown where they are to grow, because they dislike transplanting. Dill and cilantro both have a taproot that resents disturbance, and transplanted seedlings often bolt or grow poorly. Sow them direct into their final pot or bed, thinly, after the last frost for dill and in cool weather for cilantro — cilantro bolts in heat, so sow it in spring and again in late summer for an autumn crop. Chives can be sown direct or started indoors, and they will form a clump that lasts for years. Parsley can be sown direct too, though it is slower to get going than a plant started indoors.
Prepare the bed or pot before you sow: rake it fine, water it, and sow into moist soil. Cover the seed lightly, firm the soil gently, and keep it moist until germination — a dry spell at the critical moment can kill a whole sowing. Mark the row, because herb seedlings are easily mistaken for weeds and hoed off by accident. Thin the seedlings to the spacing the packet recommends — a crowded row of dill gives thin, weak plants, while a properly thinned row gives sturdy plants with plenty of leaves. Our plant spacing calculator can help you work out spacing.
Seedling care: thinning, pricking out and hardening off
Thin seedlings ruthlessly: a tray of basil left unthinned gives a mass of weak, leggy plants, while a thinned tray gives sturdy plants with room to grow. When seedlings have their first true leaves — the second pair of leaves, which look like the adult herb — prick them out into individual pots, handling them by a leaf rather than the stem, because a crushed stem kills the seedling. Pot them into fresh compost at the same depth they were growing, water them in, and keep them out of direct sun for a day or two while they settle.
Harden seedlings off before you plant them out: over seven to ten days, put them outside for longer each day, starting with a few hours in a sheltered spot and building up to a full day and night. A basil plant put straight from a warm windowsill into a cold garden will be checked for weeks, while a hardened-off plant will grow away at once. Do not plant tender herbs out until all danger of frost has passed — basil is killed by even a light frost. Our guide to damping-off seedlings covers the disease that kills seedlings in cold, damp compost, and if you lose seedlings and cannot tell why, check your local extension service for advice.
Common mistakes
The most common seed-starting mistake is sowing too deep — tiny seeds buried under compost never reach the light. The second is sowing too thickly, so seedlings crowd each other and damp off. The third is keeping seedlings in the dark after they germinate, so they grow tall and weak. The fourth is transplanting dill and cilantro, which resent it — sow them direct instead. And the fifth is giving up on slow herbs too soon: parsley that shows nothing for two weeks is normal, and rosemary seed that germinates patchily is normal too. Sow thinly, give light and warmth, be patient, and buy plants for the herbs that are slow or unreliable from seed.
| Herb | Sow indoors or direct | Germination | Notes |
|---|---|---|---|
| Basil | Indoors before last frost | Fast in warmth, about a week | Needs warmth; killed by frost |
| Parsley | Indoors or direct | Slow, 2–3 weeks | Soak seed overnight to speed it up |
| Dill | Direct | 1–2 weeks | Dislikes transplanting; taproot |
| Cilantro | Direct | 1–2 weeks | Sow in cool weather; bolts in heat |
| Chives | Indoors or direct | Steady | Forms a lasting clump |
| Chamomile | Indoors; needs light | Needs light, do not cover | Press onto compost surface |
| Rosemary, thyme, lavender | Buy plants or take cuttings | Slow and patchy from seed | Faster and more reliable as plants |
Frequently asked questions
Which herbs are easiest to grow from seed?
Basil, dill, cilantro, parsley and chives are the easiest from seed. Basil germinates quickly in warmth, dill and cilantro germinate readily but should be sown direct, parsley is slow but reliable, and chives grow into a lasting clump.
Why is my parsley seed not germinating?
Parsley is slow — it can take two to three weeks to germinate, and that is normal. Soaking the seed in warm water overnight before sowing can speed it up. Keep the compost moist, be patient, and do not give up after a week.
Should I start basil indoors or sow it outside?
Start basil indoors a few weeks before the last frost, because it needs warmth to germinate and it is killed by frost. Plant it out only after all danger of frost has passed, and harden it off first.
Can I grow rosemary from seed?
You can, but it is slow and unreliable — germination is patchy and seed-grown plants may not match the parent. Most gardeners buy a small rosemary plant or take cuttings, which are faster and more reliable.
Why do my herb seedlings fall over and die?
That is usually damping off, a fungal disease of cold, damp compost. Use fresh compost and clean trays, sow thinly, give seedlings light and ventilation as soon as they appear, and let the compost surface dry a little between waterings.