How to Overwinter Herbs and Protect Them from Frost – Complete UK Guide

Growing your own herbs is one of the most rewarding parts of gardening. Whether you’re picking fresh rosemary for roast potatoes, adding thyme to homemade soup or harvesting mint for a refreshing drink, there’s nothing quite like using herbs you’ve grown yourself.

But as autumn arrives and temperatures begin dropping, many gardeners start wondering what will happen to their herb plants during winter.

Will rosemary survive outside? Should you cut mint back? Can parsley continue growing in a greenhouse? And what should you do with basil when frost is forecast?

The good news is that many popular culinary herbs can survive a typical UK winter, provided they’re growing in suitable conditions.

However, not all herbs are equally hardy. Some tolerate freezing temperatures, while others are damaged by even a light frost.

Here at Gardening with Ben, we’re looking at how to overwinter herbs successfully, which varieties need protection, how to care for herbs in containers and what you can do to keep harvesting fresh leaves during the colder months.

Whether you’re growing herbs in a garden border, raised bed, greenhouse, polytunnel or on a kitchen windowsill, this complete guide will help you prepare for winter.

Why Do Herbs Struggle During Winter?

Herbs can experience several problems during the colder months.

Although frost is an obvious concern, freezing temperatures aren’t always the main cause of winter losses.

In many UK gardens, prolonged wet weather can be just as damaging.

Frost Damage

When temperatures fall below freezing, water inside plant tissues can freeze and damage cells.

Tender herbs such as basil are particularly vulnerable.

Hardier herbs have adaptations that allow them to survive colder conditions.

Waterlogged Soil

Many Mediterranean herbs naturally grow in relatively free-draining soils.

Rosemary, thyme and sage can struggle when their roots remain saturated during winter.

Cold, wet soil increases the risk of root damage and rot.

Reduced Daylight

Winter brings shorter days and lower light levels.

Plant growth slows, meaning herbs generally need less water and fertiliser.

Cold Winds

Strong, cold winds can dry out evergreen foliage, particularly when the soil is frozen and roots cannot replace lost moisture.

Repeated Freezing and Thawing

Plants growing in containers may be especially vulnerable when compost repeatedly freezes and thaws.

Understanding these problems helps you choose the right winter protection.

Which Herbs Can Survive Winter Outdoors in the UK?

Some herbs are naturally hardy and can remain outdoors throughout winter.

Others need shelter, while tender species must be protected from frost.

Herb	Winter hardiness	Recommended winter care
Rosemary	Generally hardy in sheltered, well-drained positions	Protect from prolonged wet and severe cold
Thyme	Generally hardy	Ensure excellent drainage
Sage	Generally hardy in suitable conditions	Avoid waterlogging
Mint	Hardy perennial	Allow foliage to die back naturally
Chives	Hardy perennial	Expect winter dormancy
Oregano	Often hardy	Protect crowns from excessive winter wet
Parsley	Hardy biennial	Protect leaves during severe frost
Bay laurel	Moderately hardy	Shelter pots from severe frost and wind
French tarragon	Hardy perennial with winter dormancy	Keep roots well drained
Basil	Frost tender	Grow indoors or replace next season
Lemon verbena	Tender to moderately hardy, depending on conditions	Protect from significant frost
Coriander	Cool-season annual	Grow under protection for winter harvests

Hardiness varies with cultivar, soil drainage, exposure, plant maturity and the severity of the winter.

In northern England, including Sheffield and surrounding areas, exposed gardens can experience significantly colder conditions than sheltered city gardens.

1. How to Overwinter Rosemary

Rosemary is one of the most popular herbs grown in UK gardens.

Its aromatic evergreen leaves are useful throughout the year, particularly for winter cooking.

Although rosemary can tolerate frost, prolonged cold combined with wet soil can cause problems.

Protect Rosemary from Waterlogging

Rosemary prefers free-draining soil.

If your garden has heavy clay, consider growing rosemary in a raised bed or container with suitable drainage.

Avoid leaving pots standing in saucers filled with water.

Should You Bring Rosemary Indoors?

Established rosemary growing in a sheltered, well-drained garden may remain outdoors throughout winter.

However, young plants and container-grown specimens can benefit from additional protection during severe weather.

A cold greenhouse, sheltered porch or bright, cool conservatory may be suitable.

Avoid placing rosemary in a very warm, poorly lit room because conditions may encourage weak growth.

Watering Rosemary During Winter

Rosemary is evergreen, so it may still need occasional watering.

Check the compost rather than watering on a fixed schedule.

Only water when necessary, and avoid saturating cold compost.

Should You Prune Rosemary in Autumn?

Avoid hard pruning late in autumn.

New growth encouraged by pruning may be vulnerable to frost.

Major shaping is generally better carried out during spring or after flowering, depending on the plant.

2. How to Protect Thyme During Winter

Thyme is a useful evergreen herb that can survive cold weather when drainage is good.

Its greatest winter enemy is often wet soil.

Improve Drainage

Thyme grows best in a sunny, free-draining position.

Avoid planting it where water collects after heavy rainfall.

In containers, use a suitable free-draining potting mix.

Protect Potted Thyme

Move pots into a sheltered position during prolonged wet or freezing weather.

Raising containers slightly above the ground can help prevent drainage holes becoming blocked.

Should You Cut Thyme Back Before Winter?

Avoid cutting thyme hard into old woody stems during autumn.

Light harvesting is usually fine, but major pruning is better timed for active growth.

Can You Harvest Thyme in Winter?

Yes. Evergreen thyme may provide leaves throughout winter.

However, growth is slower, so harvest sparingly to avoid weakening the plant.

3. How to Overwinter Mint

Mint is one of the easiest herbs to overwinter because most commonly grown culinary mints are hardy perennials.

During autumn, the above-ground growth often begins turning yellow and dying back.

This is normal.

The underground roots and rhizomes remain alive and produce new shoots when conditions improve.

Should You Cut Mint Back?

Once the foliage has died back, you can remove the dead stems.

Cut them close to ground level using clean secateurs.

Avoid disturbing the underground roots unnecessarily.

Does Mint Need Frost Protection?

Established mint growing in the ground usually survives winter without special protection.

Mint in small containers may be more vulnerable because the roots are exposed to lower temperatures.

Move pots into a sheltered position if prolonged freezing weather is expected.

Can You Harvest Mint During Winter?

Outdoor mint often produces little or no fresh growth during winter.

For winter leaves, you can grow a separate plant indoors in a bright position.

However, indoor mint still needs sufficient light and appropriate watering.

4. How to Overwinter Parsley

Parsley is a biennial herb, meaning it normally completes its life cycle over two growing seasons.

During its first year, it produces leaves.

In its second year, it usually flowers and sets seed.

Parsley can tolerate cool weather and some frost, making it useful for winter harvesting.

Growing Parsley Outdoors

Established plants may continue producing leaves during mild spells.

However, growth slows considerably during colder weather.

Protecting Parsley from Frost

A cloche, cold frame or unheated greenhouse can provide useful shelter.

Horticultural fleece may also help reduce exposure to cold winds and frost.

Remember that fleece provides limited protection during prolonged severe freezing conditions.

Can Parsley Grow in a Polytunnel?

Yes. Parsley can be grown in a polytunnel during autumn and winter.

Provide ventilation during mild weather and avoid waterlogging.

A polytunnel can improve growing conditions, but it isn’t automatically frost-free.

5. How to Keep Chives Alive Through Winter

Chives are hardy perennial herbs that naturally die back during winter.

As temperatures fall, the leaves may turn yellow and collapse.

This doesn’t necessarily mean the plant has died.

Cutting Back Chives

Once the foliage has died back, remove the dead growth.

Avoid cutting into the crown.

Winter Protection

Established chives growing in well-drained garden soil usually require little protection.

Container-grown plants can be moved into a sheltered position during prolonged freezing weather.

When Will Chives Grow Again?

Fresh shoots normally appear during spring as temperatures rise.

The exact timing depends on local weather conditions.

6. How to Overwinter Sage

Sage is another useful evergreen culinary herb.

It can survive winter outdoors in many UK gardens, but cold, wet conditions can cause problems.

Choose a Sheltered Position

Sage prefers sunshine and free-draining soil.

A sheltered border or raised bed can provide better conditions than an exposed, waterlogged position.

Avoid Heavy Autumn Pruning

Don’t cut sage hard back into old wood late in the season.

Wait until spring before removing winter-damaged growth.

Protect Young Plants

Young sage plants may benefit from additional shelter during their first winter.

Container-grown sage can be moved close to a sheltered wall or into a cold greenhouse during severe weather.

Harvesting Sage in Winter

Established plants may provide leaves throughout winter.

Harvest lightly because growth is limited during colder months.

7. How to Overwinter Oregano and Marjoram

Oregano and marjoram are closely related herbs, but their winter hardiness can vary.

Many culinary oregano varieties are hardy perennials.

Sweet marjoram is generally less hardy and may be grown as an annual in colder UK gardens.

Oregano Winter Care

Oregano often dies back partially or completely during winter.

Avoid assuming the plant has died simply because the foliage disappears.

Good drainage is important.

Remove dead stems when appropriate, taking care not to damage emerging shoots.

Sweet Marjoram Winter Care

Sweet marjoram may need frost-free protection to survive.

You can take cuttings or grow a replacement plant indoors if you want to preserve a favourite specimen.

8. How to Protect Bay Trees from Frost

Bay laurel is a popular evergreen herb, often grown as a small tree or clipped into decorative shapes.

Established bay trees can tolerate some frost, particularly in sheltered gardens.

However, severe cold and icy winds can damage leaves and shoots.

Protecting Bay Trees in Pots

Move containers close to a sheltered wall or into a cold greenhouse during severe weather.

Wrap the pot with suitable insulating material to reduce root exposure.

Avoid covering the entire plant with non-breathable plastic.

Watering Bay Trees During Winter

Bay trees remain evergreen and may need occasional watering.

Check the compost and water only when necessary.

Avoid leaving the roots saturated.

Should You Prune Bay in Winter?

Major pruning is generally better left until spring or summer.

If frost damage occurs, wait until warmer weather before assessing which stems need removing.

9. Can Basil Survive Winter in the UK?

Basil is one of the most frost-sensitive culinary herbs.

It grows best in warm conditions and can suffer damage when temperatures fall well above freezing.

Outdoor basil generally won’t survive a typical UK winter.

Bringing Basil Indoors

If you want to keep basil growing, move healthy plants indoors before cold weather arrives.

Choose a warm, bright position.

A sunny windowsill may work during autumn, but winter light levels can be insufficient.

Supplementary grow lighting may be needed for strong growth.

Watering Indoor Basil

Keep the compost lightly moist without waterlogging.

Avoid allowing the plant to sit in cold, wet compost.

Should You Take Basil Cuttings?

Yes. Basil can often be propagated from suitable stem cuttings.

This can be a useful way to grow replacement plants indoors.

However, the resulting plants still need adequate warmth and light.

For many UK gardeners, sowing fresh basil seeds in spring is the simplest approach.

10. How to Overwinter Lemon Verbena

Lemon verbena produces beautifully scented leaves that are useful for teas and cooking.

However, it is less cold-hardy than many traditional Mediterranean herbs.

During autumn, lemon verbena may shed its leaves and enter dormancy.

Winter Protection

In colder parts of the UK, container-grown plants are best moved into a sheltered, frost-free position.

A cool greenhouse with suitable frost protection can work well.

Avoid overwatering dormant plants.

When Does Lemon Verbena Regrow?

New shoots usually appear when temperatures rise during spring.

Be patient because plants may remain dormant longer than expected.

Don’t discard a leafless plant too early without checking whether the stems are still alive.

11. Can You Grow Herbs in a Greenhouse During Winter?

A greenhouse can be extremely useful for protecting herbs from winter rain, wind and some frost exposure.

However, an unheated greenhouse doesn’t guarantee frost-free conditions.

During very cold nights, temperatures inside may approach outdoor temperatures.

Suitable Herbs for an Unheated Greenhouse

Depending on conditions, you may grow:

• Parsley
• Thyme
• Rosemary
• Sage
• Chives
• Mint
• Certain hardy oregano varieties

Tender herbs such as basil generally need warmer conditions.

Greenhouse Winter Care

Ventilate during mild weather.

Water sparingly and check compost moisture.

Remove fallen leaves and dead plant material.

Inspect plants for pests and fungal diseases.

Use appropriate frost protection when temperatures are forecast to fall significantly.

12. How to Overwinter Herbs in a Polytunnel

A polytunnel provides useful shelter for herbs during autumn and winter.

It protects plants from direct rainfall and can warm up quickly during sunny weather.

However, temperatures can fluctuate considerably.

On clear winter nights, an unheated polytunnel can become very cold.

Growing Herbs in Polytunnel Beds

Hardy herbs such as parsley, chives and suitable oregano varieties may grow successfully in protected beds.

Mediterranean herbs can also be grown under cover, provided the soil drains well.

Growing Herbs in Pots

Pots are useful because they can be moved when necessary.

Keep containers away from areas where water collects.

Managing Condensation

Ventilation is important because excessive humidity can encourage fungal problems.

Open doors or vents during suitable weather, then close them when necessary to protect plants from severe conditions.

Extra Frost Protection

Horticultural fleece or an internal mini tunnel can provide additional insulation.

However, tender plants may still require heating or relocation to a frost-free space.

Gardening with Ben tip: A polytunnel is brilliant for extending the growing season, but don’t rely on the plastic covering alone to protect tender herbs from a hard frost.

13. How to Protect Herbs Growing in Pots

Container-grown herbs are often more vulnerable to winter damage than plants growing in the ground.

This is because the roots are surrounded by a relatively small volume of compost that can freeze quickly.

Move Pots into Shelter

Place containers near a sheltered wall, in a cold frame or inside a suitable greenhouse.

Raise Pots Off the Ground

Pot feet or small supports can improve drainage and prevent containers sitting in standing water.

Insulate Containers

Wrapping the outside of pots with suitable insulating material may help protect roots during freezing weather.

Avoid Waterlogging

Make sure drainage holes remain clear.

Remove saucers that collect excessive rainwater.

Group Pots Together

Grouping containers in a sheltered location can reduce exposure to cold winds.

However, leave enough space for airflow and regular inspection.

14. Should You Cut Herbs Back Before Winter?

This depends on the type of herb.

Hardy herbaceous perennials such as mint and chives naturally die back.

Their dead foliage can be removed once growth has finished.

Evergreen woody herbs such as rosemary, thyme and sage should generally not be cut back hard during late autumn.

Heavy pruning can expose plants to frost damage and encourage tender new growth.

Tender herbs such as basil may be harvested before temperatures fall, but pruning won’t make them frost-hardy.

A Simple Rule

For herbs that die back naturally, remove dead growth when appropriate.

For evergreen woody herbs, avoid heavy late-season pruning.

For tender herbs, focus on providing suitable warmth and protection.

15. How Often Should You Water Herbs During Winter?

Overwatering is one of the most common winter herb-care mistakes.

Plants generally use less water during colder months because growth slows.

However, evergreen herbs may still need occasional moisture.

Herbs Growing Outdoors

Established plants in garden soil may receive enough moisture from rainfall.

Avoid unnecessary watering during wet weather.

Herbs in Greenhouses

Check the compost regularly.

Water when needed, preferably during milder conditions.

Herbs Growing Indoors

Indoor herbs may dry out faster, particularly near radiators.

Check the compost rather than following a rigid watering schedule.

Avoid Standing Water

Never allow pots to remain in waterlogged conditions for prolonged periods.

16. Should You Feed Herbs During Winter?

Most outdoor herbs don’t need regular feeding during winter.

Growth slows considerably, and excessive fertiliser can encourage weak growth or lead to nutrient accumulation in containers.

For hardy herbs, wait until spring before assessing whether additional nutrients are needed.

Indoor herbs growing actively under suitable light may occasionally benefit from a modest feed, depending on their growing medium.

Always follow the instructions for the fertiliser you’re using.

17. How to Keep Harvesting Fresh Herbs in Winter

Although many herbs slow down or become dormant, you can still enjoy home-grown herbs during winter.

Harvest Evergreen Herbs

Rosemary, thyme and sage may provide leaves throughout winter.

Harvest sparingly to avoid weakening plants.

Grow Parsley Under Cover

Parsley can continue producing leaves during mild periods, particularly in a greenhouse or polytunnel.

Grow Indoor Herbs

Suitable indoor growing conditions can allow herbs such as basil, mint and parsley to continue growing.

Freeze Herbs During Summer

Freezing surplus herbs is an excellent way to preserve their flavour.

Chopped herbs can be frozen in suitable containers or ice-cube trays.

Dry Suitable Herbs

Rosemary, thyme, oregano and sage are commonly dried for storage.

Ensure herbs are dried thoroughly and stored in clean, airtight containers.

18. Common Winter Herb Problems and How to Fix Them

Rosemary Turning Brown

Possible causes include root damage from waterlogging, severe frost, drought or disease.

Check the soil and growing conditions before deciding on treatment.

Thyme Dying During Winter

Poor drainage is a frequent problem.

Consider growing replacement plants in a better-drained position.

Mint Disappearing

Mint naturally dies back during winter.

Wait until spring before assuming the plant has died.

Basil Leaves Turning Black

Cold temperatures can quickly damage basil foliage.

Move healthy plants into suitable warm conditions before cold weather arrives.

Mould on Herb Compost

Excessive moisture and poor ventilation can encourage mould.

Improve airflow and reduce unnecessary watering.

Yellow Leaves

Yellowing can have several causes, including overwatering, low light, natural dormancy or root problems.

Check the plant’s overall condition before applying fertiliser.

19. UK Herb Winter Care Calendar

Month	Recommended jobs
September	Assess tender herbs and take cuttings where appropriate.
October	Move frost-sensitive herbs into protection before cold nights.
November	Improve drainage, shelter pots and reduce watering.
December	Check frost protection and inspect plants for rot.
January	Continue monitoring moisture and protect from severe cold.
February	Check for winter damage and prepare for spring growth.
March	Begin gradual spring maintenance as temperatures improve.
April	Pot on suitable plants and start new sowings under protection.

These timings vary depending on the weather and your location.

In northern England, always watch for late frosts before moving tender plants outdoors.

20. Ten Mistakes to Avoid When Overwintering Herbs

1. Leaving basil outside during frost: Basil is tender and needs warm conditions.
2. Overwatering rosemary: Cold, saturated compost can damage roots.
3. Cutting woody herbs back too hard: Heavy autumn pruning can increase winter damage.
4. Assuming a greenhouse is frost-free: Unheated structures can still freeze.
5. Ignoring drainage holes: Blocked pots can become waterlogged.
6. Keeping herbs in dark rooms: Indoor plants need adequate light.
7. Feeding dormant plants unnecessarily: Most herbs require little winter fertiliser.
8. Throwing away dormant mint: Many hardy herbs regrow from their roots.
9. Leaving small pots exposed: Container roots can freeze more readily.
10. Moving tender herbs outdoors too early: Late spring frosts can damage young growth.

Frequently Asked Questions About Overwintering Herbs

Can rosemary survive winter outside in the UK?

Yes, rosemary can survive many UK winters outdoors, particularly in sheltered positions with free-draining soil. Severe cold and prolonged wet conditions can still cause damage.

Should I cut mint back for winter?

You can remove dead mint foliage once the plant has naturally died back. The underground roots usually remain alive and regrow in spring.

Can basil survive in an unheated greenhouse?

Basil is frost tender and generally needs warmer conditions than an unheated UK greenhouse can reliably provide during winter.

Does thyme survive frost?

Many thyme varieties tolerate frost well, especially when grown in free-draining soil.

Can parsley grow during winter?

Parsley may continue growing slowly during mild winter weather. Protection from severe frost can help preserve usable leaves.

Should herbs be watered in winter?

Yes, when necessary, but most herbs require less water during winter. Avoid waterlogging and check compost moisture before watering.

Can herbs survive in a polytunnel?

Many hardy herbs can overwinter successfully in a polytunnel. Tender species may need additional frost-free protection.

Which herbs should I bring indoors for winter?

Basil, lemon verbena and other frost-sensitive herbs generally need protection. The exact requirements depend on the species and growing conditions.

Should I fertilise herbs during winter?

Most outdoor herbs don’t need feeding while growth is slow or dormant.

When can I move herbs outside in spring?

Hardy herbs can remain outdoors, while tender herbs should only be moved outside permanently once frost risk has passed and they’ve been hardened off.

Final Thoughts: Keeping Your Herbs Healthy Through Winter

Overwintering herbs successfully is largely about understanding which plants are hardy and which need extra protection.

Rosemary, thyme and sage can often remain outdoors if drainage is good.

Mint, chives and many oregano varieties naturally die back before returning in spring.

Parsley can provide useful winter harvests, particularly under protection.

Tender herbs such as basil and lemon verbena need more careful treatment when temperatures begin falling.

The most important winter gardening jobs are preventing waterlogging, protecting vulnerable plants from frost and avoiding unnecessary pruning or feeding.

With a little preparation during autumn, you can reduce winter losses and enjoy a healthy herb garden when spring arrives.

And remember, growing herbs is all about experimenting and discovering what works best in your own garden or allotment.

Keep smiling, keep shining, keep gardening with Ben!