How to Protect Plants From Frost in the UK: Top Tips & Must-Have Tools

06/10/2021 Rob Walter

Learn how to protect your plants from frost in the UK using WM James & Co’s expert tips. Keep your crops safe during winter weather with our easy guide. Read on for more.

It's that time of year again: the weather is getting colder, and we're all beginning to think about how we protect plants from frost. Fail to do so, and you may end up with some very sad-looking plants come springtime!

Luckily, our gardening experts at William James have come together to share their top tricks for how to protect plants from frost this winter.

If you’re in a rush, here are our top tips for protecting your plants from frost at a glance

Protect vulnerable plant areas with thick layers of mulch.
Secure mulch in place with stones or garden fleece.
Ensure that any protective measures you use, such as sheeting or fleece jackets, are anchored into the ground to protect against wind.
Cover fruit trees with thick layers of mulch.
Bring vulnerable plants inside, either in your shed, greenhouse or your windowsill.

What Plants Need Protection from Frost?

Which plants need protection from frost? Some need it more than others, especially frost-tender plants.

Berry bushes and trees need extra protection from winter weather, which can damage their blossoms.

Other plants that require protection during winter include...

Camellias
Cyclamen
Azaleas
Hellebores

Even a small amount of frost in early spring can prevent blooms in summer. Tender plants, young seedlings, and potted plants are all vulnerable to frost damage and should be protected if possible.

Note: Although hardy plants, winter vegetables like potatoes, broad beans, and carrots should be protected from the harsher frosts of winter with fleece tunnels and horticultural garden fleece to ensure their growth and health.

What if My Garden Doesn't Experience Frost?

If you live in an area where it never gets cold enough to damage your plants (please let us know where so we can visit!), that doesn't mean you shouldn't protect them from the cold.

Even if temperatures don't drop low enough for frost to form, low temperatures can still damage plants by slowing down their growth and making them more vulnerable to disease.

Our windbreak netting is ideal for protecting your garden from colder conditions. It's lightweight and flexible, so it can create a protective barrier against cold winds without blocking out too much light. It's ideal for milder winters.

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How to Protect Plants from Frost in the UK

Protecting plants from frost should be at the top of your list of jobs if you're gardening in October.

There are many different ways to protect your garden plants from freezing temperatures over winter, depending on the type of plant you care for and the damage your plants can sustain.

Here are our tips for doing just that…

1. Cover the Soil With a Thick Layer of Mulch

The first step is ensuring that the soil around plant roots doesn't freeze. Freezing soil creates expansive pockets of water or frost pockets, which drain energy and nutrients away from vulnerable root systems, causing permanent damage.

This isn't usually a problem for plants in small pots, but for larger plants, you'll need to protect the soil from freezing by covering it with a thick layer of mulch – this will help insulate the root system and ground.

To prevent the mulch from being blown away by heavy winds, secure it in place with stones or plant pots.

Note: If you keep your plants in a greenhouse or glasshouse, make sure at least ten centimetres of warm air is above the plant to protect it from frost damage.

2. Use Horticultural Fleece or Plant Jackets

In an outdoor garden, this can be achieved using horticultural fleece or plastic sheeting – make sure to secure it properly with pegs and use enough layers so that no light penetrates through the plant.

Covering any outdoor pots, even with something as simple as a sheet of thick cardboard, will protect the leaves overnight.

If your garden is susceptible to heavy bouts of frost, protect against it by covering up vulnerable shrubs and trees with sheets or blankets overnight; this will prevent them from sustaining any severe damage.

Our Frost Protector Jackets are very popular among gardeners. They are lightweight, easy to use and can be reused year after year.

Plus, they feature an integral drawstring, which can be tightened, creating a microclimate that retains heat and protects your plants from the harsh elements.

3. Protecting Indoor House Plants from Frost

If your house is particularly cold, protect against light frost on window sills and other surfaces with sheets of plastic or even newspapers – this prevents ice from forming between panes of glass.

This will help protect your plants from frost damage and prevent condensation in the winter, which can cause dampness.

You can also opt to move your plants away from the window when the temperature drops overnight to help keep them warmer.

How to Protect Garden Trees from Frost

Like smaller plants, trees are also susceptible to frost damage - the most common being 'frost cracks' or 'sun scalds'.

Frost cracks occur when the sap in a tree's trunk freezes and expands, causing the bark to split.

Sun scalds happen when the sun heats the bark during the day, causing it to expand. When the temperature drops at night, the bark contracts and can crack.

To protect trees from frost damage, you should:

Water them well before a cold snap to help them withstand the frost.
Wrap the trunks of young trees in horticultural fleece or bubble wrap to insulate them.
Cover the roots with a thick layer of mulch or ground cover.
Place a stake next to any leaning trees to support them if they should crack under the weight of the frost.

How Should I Protect Fruit Trees in Winter?

Fruit trees need extra care throughout winter to ensure they remain healthy during the colder months. This is particularly important for those who have recently planted their tree as it's still getting used to its new environment.

If your garden is particularly frost-prone, protect trees and plants against heavy frosts by placing a thick layer of mulch over exposed roots and stems before covering them with straw, leaves or bark chips.

To prevent the mulch from being blown away by heavy winds, secure it in place with stones or plant pots.

What are the Most Common Plant Frost Protectors?

You have a few options if you want to protect your plants from frost, depending on the types of plants you grow and the type of garden you have.

A balcony garden with potted plants needs a different approach from a low-lying vegetable garden where plants are grown directly in the ground.

Type of Plant Frost Protector	Explanation of Use
Horticultural fleece & plant jackets	The best way to protect plants from frost damage is by using our plant frost jackets & horticultural fleece – these protect your garden from very low temperatures, are simple to use & easy to move around depending on where they need to be used.
Thick sheet of cardboard or newspaper	For small plants or pots. If using newspaper, make sure to protect it from the wind so it doesn't get blown away & cover the plant in mulch before putting down your protectors.
Heated water bottles	If you're on a budget, hot water bottles offer flexible protection for the whole night & can be easily moved around in small areas. They can protect plants from frost & cold snaps but need to be replaced every day/night.
Water sheets	On the opposite end of the price range, water sheets can protect plants from as low as minus 23 degrees. They're easy & quick to install but also very heavy, so they need a lot of anchoring into place.
Electric plant protectors	Perfect for covering larger areas & a good option for covering many plants at once.

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Does Netting Protect Plants from Frost?

Some types of garden netting, like our dark green windbreak netting, can help protect plants from frost damage by creating a barrier between the plant and the cold air.

These nets have a close mesh, which protects plants from cold winter winds. Secure the netting in place so it doesn't blow away in strong winds, and cover any gaps with straw or leaves to insulate your plants further.

When using netting to protect plants from frost, make sure to remove it once the risk of frost has passed, as it can restrict the plant's growth. You should take extra care when using netting to protect younger tender plants.

Using a cold frame can help to create a warmer environment for these plants to grow in.

Note: Netting with a large mesh will not protect against frost, as cold air can still pass through it. Therefore, it's important to invest in the right netting for your pants.

Find the Best Crop & Plant Protection

What Exactly is Frost & How is it Formed?

Frost is simply a deposit of white crystals on the ground or other surfaces, formed when water vapour in the air changes directly to ice.

Water's freezing point varies depending on the contamination, but generally speaking, it freezes at 0 Celsius.

The key thing about frost is that the colder it gets, the more damaging it can be. Plants will start to feel the impact of a freezing night and need protection; at lower temperatures, the damage increases exponentially.

It's essential to protect plants from colder temperatures in winter because the damage caused can be irreparable.

When Does Frost Occur in the UK?

Typically, frost occurs between October and March in the UK. However, any time the temperature drops below freezing, and there's a wind chill factor involved, you should protect your plants from frost.

The north of the UK tends to get colder weather than the South, which means gardeners in the North often have more work to do when it comes to protecting plants from frost!

What Causes a Cold Snap?

A cold snap is an abrupt drop in temperature that lasts for two or three days, typically between October and March. It occurs due to large pockets of cool air moving across the UK from the north, a polar vortex.

In addition to this, cold air drifts over the UK at night from the North Sea and can cause a sudden drop in temperature.

Therefore, it's vital to take steps to protect your plants, especially tender and young plants, in cold weather.

How Does Frost Damage Plants?

Frost is a plant's worst enemy, as it causes irreparable changes—both physical and chemical. Plants are made up of cells filled with watery sap that circulates nutrients around them.

When these cells freeze, they can rupture and burst, permanently damaging your plants' cell walls.

This results in what's known as 'frost burn', which causes browned or blackened leaves on both evergreens and deciduous plants.

Another obvious result of unprotected plants being exposed to freezing temperatures overnight will be dead or discoloured foliage, but that's not the end of the story.

If left for too long, your plants could also suffer root damage or death, which could lead to further problems.

Taking the time to protect plants from frost damage as part of your winter gardening jobs will prevent these symptoms and ensure you have healthy flowerbeds come springtime!

Note: Where possible, protect your plants from frost at night by bringing them inside.

Summary: Our Top Frost Protection Tips

Ensuring your plants are shielded from frost and snow is crucial to maintaining their health and longevity. Frost can cause cells within plants to freeze and burst, leading to irreparable damage and even death.

By protecting plants from frost, you can prevent issues such as frost burn, root injury, and halted growth, thereby fostering a robust and thriving garden throughout winter and into the growing season.

Keep your plants warm and cosy this winter, and shop our range of garden fabric online today!

You can read more about the Plant Protection Netting We Recommend For Your Garden (& How To Use It) to keep it blossoming year-round.

More Gardening Tips and Advice in Our Blog

FAQs

What is Best to Cover Plants from Frost?

Horticultural fleece is one of the most effective ways of protecting your plants against frost. The close-woven mesh material is lightweight and breathable, allowing water to pass through the fabric while protecting the plant from any harmful cold temperatures.

Can You Put Potted Plants in a Shed to Protect from Frost?

Moving potted plants indoors to a shed, garage, or house shields them from harsh temperatures. Only leave them inside for a few days, as they need light and air circulation. Keep them in a spot with natural light if possible. Alternatively, use a frost cloth or horticultural fleece to wrap the pot for extra cold protection.

Can You Use Bubble Wrap Instead of Horticultural Fleece?

Some gardeners do use bubble wrap to protect their plants from frost, but we always recommend horticultural fleece or plant jackets. These nets are specifically made to keep plants warm in cold climates and provide better breathability than bubble wrap.

What is a Plant Jacket?

A plant jacket is essentially a 'jacket' of fleece netting that's put over a pot to provide extra heat and insulation.

Will Cardboard Boxes Protect Plants From Frost?

Yes, cardboard boxes can protect plants from frost by providing a layer of insulation. Ensure the boxes are large enough to cover the entire plant and weigh them down to prevent them from blowing away. This simple method helps retain heat and shield plants from cold temperatures.

Does Netting Protect Plants from Frost?

Given that the netting is made with an ultrafine mesh, it will provide some insulation and prevent frost from directly touching the plants.

Our Horticultural Fleece netting is made from 17gsm spun-bound polypropylene, which is lightweight and easy to use. It provides protection from frost, harsh winds, and pests while still allowing air and water to pass through. This helps maintain a healthy environment for plants to thrive in.