Tarragon is the herb that makes chicken, fish and béarnaise sauce taste French — aniseedy, warm and unlike anything else in the herb bed. French tarragon, the culinary kind, is grown from cuttings because it rarely sets viable seed, so seed packets are usually Russian tarragon, which is hardier but milder in flavour. Either way, seed is the way most gardeners start.
Tarragon seed germinates best with a gentle indoor start, where you can keep it warm, damp and undisturbed. This guide covers the surface sowing it prefers, the timing that gets plants established before summer, and the one thing tarragon hates more than anything else: wet feet. Tarragon can be started indoors or direct-sown — its sowing method is listed as "both" — and indoor sowing is the better choice if you want an earlier start, more even germination, or plants ready for the first warm weeks of the season. This crop is in the Asteraceae family, needs full sun, and takes 60–90 days to reach maturity, so the timing below is built around those facts, not guesswork.
Tarragon at a glance
| Growing factor | What tarragon need |
|---|---|
| Days to germination | 10–14 |
| Sowing method | both |
| Days to maturity | 60–90 |
| Soil pH | 6.0–7.5 |
| Spacing | 18–24 inches |
| Sun | full sun |
| Cold tolerance | hardy |
When to start tarragon seeds indoors
In Zones 3–5, start indoors 6–8 weeks before your last frost. In Zones 6–8, 4–6 weeks is enough. In Zones 9–10, sow in late winter and plant out in early spring. In frost-free Zones 11–13, sow in the cooler months — tarragon dislikes hot, humid summers and does best with a mild start. Check your local extension service for frost dates, or use our frost-date calculator and seed-starting calculator.
As a rule, work backwards from your last frost: sow indoors 6–8 weeks before it if you are starting indoors at all, and check the seed packet against the germination time of 10–14 days. Our seed-starting calculator does the backwards maths for you, and the germination-time calculator helps you plan around that 10–14-day window. If you are unsure of your zone, the hardiness-zone finder will confirm it.
What you need
a seed tray or small pots, fine seed-starting mix, a clear lid or cling film, a spray bottle, a grow light or bright windowsill, and small scissors for thinning. Tarragon needs sharp drainage, so a light, gritty mix is better than a heavy, peaty one.
You will also want a spray bottle or a watering can with a fine rose, and a notebook to record the sowing date — germination takes 10–14 days, and it is easy to forget when you sowed.
Step by step: starting tarragon seeds indoors
- Fill your containers. Fill trays or pots with fresh, damp seed-starting mix — not garden soil, which is too heavy and can carry disease. Press it down lightly and level the surface.
- Sow the seed. Sow tarragon seed on the surface of damp seed-starting mix and press it in lightly — the seed is small and germinates best with light. Cover with a clear lid and keep the tray warm and bright. Germination takes 10–14 days. Thin to one seedling per cell once they have two true leaves, snipping the extras rather than pulling them, so the roots of the survivors are not disturbed.
- Cover and label. Cover the tray with a clear lid or cling film to hold humidity, and label it with the crop and the date. Put it somewhere warm and bright, out of direct sun until seeds sprout.
- Wait for germination. Germination takes 10–14 days. Check the tray daily, mist the surface if it dries, and be patient — uneven germination is normal, especially for slow crops. Our germination-time calculator helps you track the window.
- Remove the cover. As soon as seedlings emerge, take the lid off. Good airflow from this point on is what prevents damping off.
- Give them light. Move the tray under a grow light or to your brightest window immediately — seedlings stretch within a day or two if the light is weak.
- Thin and pot on. Thin to one seedling per cell once they have two true leaves, snipping the extras rather than pulling them. Pot on into larger pots when roots show at the drainage holes, keeping the seedlings at the same depth.
- Feed lightly. Once seedlings have two sets of true leaves, feed with a half-strength liquid feed every week or two. Do not overfeed — soft, overfed seedlings are more likely to damp off and less likely to harden well.
Light for seedlings
Give tarragon seedlings 14–16 hours of bright light a day. A sunny windowsill works in spring, but a grow light a few inches above the leaves gives sturdier plants. Leggy tarragon rarely recovers well, so do not leave seedlings in dim light hoping they will catch up.
Watering seedlings
Tarragon has low water needs and is easily killed by overwatering. Keep the mix just damp while seeds germinate, then let the surface dry between waterings. Water from below and always let the tray drain fully. Damping off is the main risk in the first weeks. Our watering calculator can help you work out how much water your seedlings need as they grow.
Hardening off
Tarragon is hardy, so hardening off is straightforward: 7–10 days of increasing outdoor time, starting in sheltered shade and building to full sun. It can tolerate a light frost once hardened, but bring young plants in if a hard freeze is forecast.
Transplanting outdoors
Plant out after the last frost in full sun, in light, well-drained soil. Space plants 18–24 inches apart — tarragon spreads into a bushy clump. Our plant-spacing calculator works out the layout. Do not plant it in heavy, wet soil; if your soil is clay, grow it in a raised bed or a pot with gritty mix. For the full picture — soil, feeding, pests and harvest — see our complete growing tarragon guide.
Common problems and fixes
| Problem | Fix |
|---|---|
| Seeds do not germinate | Seed buried too deep or kept too cool. Sow on the surface, keep the tray warm and bright, and allow the full 10–14 days. |
| Damping off | Stems collapse at soil level. The mix was too wet. Water from below, remove the lid once seeds sprout, and give the tray good airflow. |
| Leggy seedlings | Not enough light. Move the light closer and give 14–16 hours a day. |
| Seedlings yellow and stall | Usually overwatering or a mix that stays wet. Let the surface dry between waterings and make sure pots drain freely. |
Seeds do not germinate
Seed buried too deep or kept too cool. Sow on the surface, keep the tray warm and bright, and allow the full 10–14 days.
Damping off
Stems collapse at soil level. The mix was too wet. Water from below, remove the lid once seeds sprout, and give the tray good airflow.
Leggy seedlings
Not enough light. Move the light closer and give 14–16 hours a day.
Good companions for tarragon include tomatoes, peppers, marigolds, cabbage. Watch out for aphids, slugs, thrips — check young plants regularly, and deal with pests early while plants are small. Our pest-identifier helper can help you work out what you are looking at.
Frequently asked questions
How long do tarragon seeds take to germinate?
10–14 days in warm, bright conditions. Keep the surface damp and do not bury the seed.
Is seed-grown tarragon the same as French tarragon?
Usually not — seed packets are generally Russian tarragon, which is hardier and milder. True French tarragon is propagated from cuttings because it rarely produces viable seed.
Can I direct sow tarragon?
Yes, tarragon can be direct-sown once the soil warms, but indoor sowing gives more even germination and an earlier start.
How far apart should tarragon plants be?
18–24 inches apart in full sun and well-drained soil.
Does tarragon come back every year?
Yes, it is hardy and perennial in most zones. Cut it back in autumn and it regrows from the roots in spring.