Transplanting is the moment a herb moves from the shelter of a pot or tray into the open ground or a larger container, and it is the moment when most young herbs are lost. A seedling that has grown in warmth, still air and steady moisture is suddenly exposed to wind, sun, cold nights and dry soil, and if the move is too abrupt, the plant stops growing for weeks — gardeners call this transplant shock — or it dies outright.
The answer is to prepare the plant, prepare the ground, and move it gently. Harden the plant off over a week or more, plant on a mild, cloudy day, water it in well, and protect it for its first days outside. Some herbs — dill and cilantro in particular — dislike transplanting so much that they should be sown where they are to grow instead. This guide covers the method, the timing, and which herbs need special care. If you are unsure about timing in your area, check your local extension service for the planting dates that fit your climate.
Hardening off: the step gardeners skip
Hardening off is the gradual exposure of a young plant to outdoor conditions, and it is the single most important step in transplanting. A basil plant that has lived on a warm windowsill has soft leaves, a thin skin, and no tolerance for wind or cold. Put it straight outside and it will wilt, scorch, or stop growing for weeks. Harden it off over seven to ten days: put it outside for a few hours in a sheltered spot on the first day, bring it in at night, and increase the time outside each day until it is spending the full day and night outdoors. By the end of the week, the plant will have toughened its leaves and adjusted to the temperature swings, and it will grow away at once when it is planted.
Start hardening off when the plant is sturdy, with several pairs of true leaves, and when the weather is mild — do not harden off in a cold snap or a gale. Keep watering the plant through the process, because a plant in a small pot dries out fast outdoors. And do not rush it: a week of hardening off is a small price for a plant that grows away immediately, compared with a plant that sits still for a month after a sudden move. Tender herbs such as basil and lemongrass need the full hardening-off period; hardy herbs such as chives and thyme need less.
When to transplant herbs
Transplant tender herbs only after all danger of frost has passed. Basil is killed by even a light frost, and a plant set out too early will be lost to a single cold night. Hardy herbs such as rosemary, thyme, sage and chives can be planted out earlier, in spring, once the soil can be worked. Parsley and mint can be planted out in spring too, though they will grow faster if they wait for warmer weather. Use our frost date calculator to find your last frost date, and treat it as an average — frost can come a week or two either side, so keep a fleece handy for the first weeks after planting.
Transplant on a mild, cloudy day, or in the evening, so the plant does not face full sun in its first hours outside. Avoid transplanting in the heat of the day, in strong wind, or into dry soil — all three increase transplant shock. If you must transplant on a sunny day, shade the plant with a cloche, a pot, or a piece of fleece for a day or two until it settles. And transplant when the plant is the right size: a seedling with two or three pairs of true leaves is ready, while a plant that has been in its pot so long that its roots are circling the bottom will struggle to establish.
How to transplant step by step
Water the plant well an hour before you move it, so the compost holds together and the roots are full of water. Prepare the planting hole in advance: dig it a little wider than the pot, fork in a little compost, and water the hole. Turn the pot on its side and slide the plant out gently, holding it by the root ball rather than the stem — a seedling held by its stem can be crushed, while one held by its leaves or its root ball is safe. If the roots are circling the bottom of the pot, tease them out gently so they can grow into the surrounding soil.
Set the plant at the same depth it was growing in the pot — no deeper, except for basil and tomatoes, which can be planted a little deeper because they root from the stem. Firm the soil gently around the roots, water it in well, and mulch around the plant to hold moisture — but keep the mulch clear of the stem. For Mediterranean herbs such as rosemary and thyme, use a gravel mulch rather than a moisture-holding mulch, so the crown stays dry. Our plant spacing calculator can help you work out how far apart to plant.
Herbs that dislike transplanting
Some herbs should not be transplanted at all. Dill and cilantro both have a taproot that resents disturbance, and a transplanted seedling often bolts or grows poorly — sow them direct where they are to grow. Parsley also has a taproot, but it transplants better than dill or cilantro if it is moved young and with a good ball of compost around its roots. Fennel is similar to dill and is best sown direct. If you have already started dill or cilantro in trays, transplant them when they are very young, handle the root ball as little as possible, and water them in well — but expect some losses, and sow a direct backup at the same time.
Other herbs transplant well if they are handled gently. Basil, mint, parsley, chives and sage all transplant readily from pots. Rosemary and lavender transplant well as young plants, but an established rosemary shrub is hard to move — its roots are deep and brittle, and a moved plant often dies. If you must move an established woody herb, do it in spring, take a large root ball, cut the top back lightly, water it well, and take cuttings first as insurance.
Aftercare: the first two weeks
The first two weeks after transplanting decide whether the plant thrives or struggles. Water regularly, so the soil around the roots never dries out completely, but do not waterlog it — a newly transplanted herb in wet soil will rot. Water at the base in the morning, and check the soil daily in hot weather. Protect the plant from strong sun and wind for the first few days with a cloche or a piece of fleece, and remove the protection once the plant is growing again. Do not feed a newly transplanted herb — it cannot use fertiliser until its roots are established, and feeding can burn the roots. Wait a few weeks, then feed lightly if the plant looks hungry.
Watch for signs of trouble. Wilting in the first day or two is normal, and the plant should recover overnight; wilting that does not recover means the roots are damaged or the soil is too dry, so water deeply and shade the plant. Yellowing leaves can mean the plant is too wet or too cold — check the soil and the weather, not the fertiliser. Slugs love young transplants, so protect them with a ring of grit or a copper collar, and see our guide to slugs and snails control for more options. If a transplant fails and you cannot tell why, check your local extension service for advice on the symptoms you are seeing.
Common mistakes
The most common transplanting mistake is skipping hardening off — a plant moved straight from a warm room to the open garden will be checked for weeks. The second is transplanting tender herbs before the last frost, so a single cold night kills them. The third is transplanting dill and cilantro, which should be sown direct. The fourth is planting too deep, which buries the stem and invites rot — set the plant at the same depth it was growing. And the fifth is feeding a newly transplanted herb, which burns roots that have not yet established. Harden off, plant on a mild day, water in well, and leave the plant alone to settle — patience in the first two weeks pays for itself all season.
| Herb | Transplanting | Hardening off | Notes |
|---|---|---|---|
| Basil | After last frost only | Full 7–10 days | Killed by frost; plant on a mild, cloudy day |
| Mint | Spring, into its own pot | Moderate | Always in a pot; spreads aggressively |
| Parsley | Spring; move young | Moderate | Taproot; move with a good compost ball |
| Rosemary, thyme, sage | Spring; young plants | Moderate | Established woody plants are hard to move |
| Chives | Spring | Light | Hardy; transplants readily |
| Dill, cilantro | Do not transplant | — | Sow direct where they are to grow |
| Lemongrass | After last frost, warm spot | Full 7–10 days | Tender; bring under cover before frost |
Frequently asked questions
When can I plant basil outside?
Only after all danger of frost has passed and the soil is warm — basil is killed by even a light frost. Harden it off over seven to ten days first, and plant it on a mild, cloudy day or in the evening.
Do I need to harden off herbs?
Yes — especially tender herbs such as basil and lemongrass. Put them outside for a few hours a day in a sheltered spot, increasing the time over seven to ten days until they spend the full day and night outside. Hardy herbs such as chives and thyme need less hardening off.
Which herbs should not be transplanted?
Dill and cilantro dislike transplanting because of their taproots — sow them direct where they are to grow. Fennel is the same. Parsley transplants better if it is moved young with a good ball of compost around its roots.
How deep should I plant a transplanted herb?
At the same depth it was growing in the pot — no deeper. The exception is basil, which can be planted a little deeper because it roots from the stem. Planting too deep buries the stem and invites rot.
Why did my transplanted herb wilt and die?
Wilting that does not recover overnight usually means root damage, dry soil, or cold. Water deeply, shade the plant, and check the soil. If the plant was moved without hardening off, or before the last frost, transplant shock or frost is the likely cause.