Herbs in winter fall into three groups, and knowing which group each herb belongs to is the whole of winter herb care. Hardy herbs such as rosemary, thyme, sage, chives and mint will survive winter outdoors in most temperate zones with a little protection. Half-hardy herbs such as parsley and coriander will survive a mild winter but not a hard freeze. Tender herbs such as basil, lemongrass and stevia will not survive frost at all, and they need to come indoors or be treated as annuals. This guide explains how to care for each group, how to protect herbs outdoors, and how to keep harvesting through winter.
Herbs are, on the whole, tougher than they look. Many come from Mediterranean hillsides, where winters are cold and wet, and they are built to cope with poor soil and cold nights. What they do not cope with is wet feet in cold soil: most herb losses in winter are caused by wet, not by cold. A rosemary in sharp, free-draining soil will survive a frost that kills the same plant in wet clay. Drainage, more than warmth, is the key to winter herb survival, and it is the first thing to get right.
Hardy herbs outdoors
Rosemary, thyme, sage, oregano, chives, mint and bay are hardy in most temperate zones, and they need little winter care beyond good drainage and a little protection. Do not feed them in winter, and do not water them unless the soil is dry — they prefer to be on the dry side. Mulch around them lightly with gravel or grit rather than a thick organic mulch, because organic mulch holds moisture against the crown and can cause rot in herbs that like sharp drainage. Our growing rosemary, growing thyme, growing oregano, growing sage and growing mint guides cover the growing side of each herb.
Rosemary deserves special care, because it is hardy in mild zones but borderline in cold ones. In zones 7 and above it usually survives outdoors with a sheltered position and sharp drainage. In zones 5 and 6 it needs a warm wall, a mulch of gravel, and fleece on the coldest nights, and it may still be damaged in a hard winter. In zones 1 to 4 it is best grown in a pot and brought under cover for winter. The same logic applies to bay, which is hardy in mild zones but needs protection or a pot in cold ones. If a hardy herb looks dead in spring, be patient and scratch a stem: many herbs leaf out late, and a plant that looks dead in March can be growing well by May.
Half-hardy and tender herbs
Parsley is biennial and often survives a mild winter, especially under a cloche or fleece, and it is worth protecting because second-year parsley is the first fresh herb of spring. Coriander and dill are annuals that will not survive a hard frost, but they can be sown under cover in late winter for an early crop. Chives die back in winter and regrow from the roots in spring — cut them back in autumn, mulch lightly, and leave them alone. Our growing parsley, growing dill and growing chives guides cover these in detail.
Tender herbs — basil, lemongrass, stevia, and tender varieties of mint and scented geranium — must come indoors before the first frost, or be treated as annuals and replaced in spring. If you bring basil indoors, give it the brightest windowsill you have, keep it warm, water sparingly, and accept that it will not grow as well indoors as it did outside. It is often better to harvest basil before the frost, make pesto or dry the leaves, and start fresh plants in spring. Lemongrass can be lifted, potted and kept in a bright, frost-free place, and divided in spring. If you are unsure whether a herb is hardy in your zone, check your local extension service for advice.
Herbs in pots in winter
Herbs in pots are more vulnerable than herbs in the ground, because a pot freezes harder and dries out faster, and wet compost in a cold pot can rot roots. Group pots together against a sheltered wall, raise them on pot feet so water drains away, and wrap the pots in bubble wrap or hessian to insulate the roots. Water sparingly — pots need far less water in winter — and do not feed them. Move tender potted herbs under cover before the first frost, and keep hardy potted herbs where they get some sun and are sheltered from cold wind. Our winter frost protection guide covers covers and cold frames, and the winter houseplant care guide covers the herbs that come indoors for winter.
Mint in a pot deserves a warning: it is vigorous and will take over a bed if planted in the ground, which is why most gardeners grow it in a pot. In winter, a potted mint dies back and looks dead, but the roots are alive and it will regrow in spring. Do not throw it away in January because it looks dead — wait until spring.
Harvesting herbs in winter
Hardy herbs can be harvested lightly through winter, and a few sprigs of rosemary, thyme or sage in a winter stew are one of the pleasures of the season. Harvest on a mild day, in the middle of the day, and take only a little — the plant is not growing fast enough to replace heavy picking. Do not harvest frozen herbs: frozen leaves bruise and lose flavour, and picking them damages the plant. Use scissors or a sharp knife, cut above a leaf joint, and never strip a plant bare in winter. Parsley under a cloche can be picked through a mild winter, and chives will regrow from the base in spring. If you want a reliable winter herb supply, dry or freeze herbs in summer and autumn: rosemary, thyme, oregano and sage dry well, and parsley, basil and mint freeze well in ice cubes or bags.
Soil and drainage for winter herbs
If your herbs are in heavy soil, winter is the time to notice the problem, even if you cannot fix it until spring. Herbs in wet clay will sit in water all winter, and their roots will rot. The fix is to improve drainage: add grit and compost, raise the bed, or move the herbs to a raised bed or a pot with free-draining mix. Do not dig wet clay in winter — it destroys the structure. Note the problem now, and fix it in spring when the soil is workable. Our soil drainage improvement and sandy soil improvement guides cover the soil side, and the winter soil preparation guide covers winter soil work in general. A herb bed on a slight slope, or a raised bed, will always do better in winter than a flat bed in heavy soil.
Common mistakes
The most common mistake is overwatering herbs in winter, which rots roots — herbs prefer to be dry in winter. The second is mulching Mediterranean herbs with thick organic mulch, which holds moisture against the crown and causes rot; use gravel or grit instead. The third is leaving tender herbs outside until the first frost has already damaged them. The fourth is feeding herbs in winter, which they cannot use and which produces soft growth that frost damages. The fifth is throwing away a herb that looks dead in winter — mint, chives and many others die back and regrow in spring. The sixth is planting mint in the ground, where it takes over, instead of in a pot. And the seventh is harvesting too heavily in winter, when the plant cannot regrow. If you are unsure about a herb's hardiness in your area, check your local extension service for advice.
Frequently asked questions
Which herbs survive winter outdoors?
Rosemary, thyme, sage, oregano, chives, mint and bay survive outdoors in most temperate zones, if the drainage is good. Parsley often survives a mild winter. Basil, lemongrass and stevia will not survive frost and must come indoors or be treated as annuals.
Should I water herbs in winter?
Only if the soil is dry, and sparingly. Herbs prefer to be on the dry side in winter, and wet roots in cold soil rot easily. Water on a mild day, in the morning, and do not water if rain is forecast or the ground is frozen.
How do I protect rosemary in winter?
Give it a sheltered position, sharp drainage, and a mulch of gravel rather than organic matter. In cold zones, cover it with fleece on the coldest nights, or grow it in a pot and bring it under cover. Do not feed it in winter.
Can I harvest herbs in winter?
Yes, lightly. Pick a few sprigs of hardy herbs on a mild day, and do not strip the plant. Do not harvest frozen herbs. For a reliable winter supply, dry or freeze herbs in summer and autumn.
Why did my herbs die over winter?
Usually wet, not cold. Herbs in heavy, wet soil rot over winter, especially Mediterranean herbs that need sharp drainage. Improve drainage, raise the bed, or grow herbs in pots with free-draining mix, and mulch with gravel rather than organic matter.