8 essential tips to protect plants from frost, recommended by our garden experts

While gardens can look gorgeous under a cover of silver frosting, the reality of frost is not so magical. To protect plants from frost during the winter months, experts reveal the essential tasks to tackle.

Similar to protecting your garden from heavy rain, it's important to undertake several key jobs to give your best winter bedding plants a better chance of staying healthy during bracing winter temperatures and harsher living conditions. Particularly frost, which has the potential to kill plants, causing damage to lawns and stunting the growth of any fledgling shrubbery.

Follow these essential winter lawn care tips and practical garden chores checklist to protect your plants and keep your plot in the best possible condition throughout the cold, wet and frosty winter months.

8 essential tips to protect plants from frost this winter

“Dealing with frost is an annual battle that every gardener faces, and while some damage is almost inevitable, there are several easy methods you can deploy to significantly reduce the impact it has on your plants and lawn," says Josh Novell, garden expert and director of Polhill Garden Centre.

“Frost doesn’t have to undo all of the hard work you have done throughout the year in your garden, and taking some time to prepare your outdoor space in the right way before the temperatures drop will make your life a lot easier come the spring.”

1. Trim and prune for prevention

Give your plants the best chance of survival by carrying out essential pruning to remove dead branches that could potentially spread disease to healthier parts of the plant. Just avoid the plants you should never deadhead as you could do more harm than good.

"Before the first frost, you should prune your garden to help lower the chance of illness and damage," says Josh. "Eliminating sick or dead branches and stems improves airflow and avoids moisture accumulation, which can cause problems with frost."

"Prune dormant shrubs and trees in December to encourage healthy growth," advises Amy Stubbs, project and development manager at British Garden Centres. "Shape hedges, grape vines, clematis, and fruit trees. December is the best month to prune climbing roses, removing diseased or damaged growth. Guide new shoots for support to encourage a beautiful spring display."

Josh Novell

Josh has over six years' worth of experience in the horticulture industry. He began his career as a strategy manager before working his way up to become a director and is now a key part of the day-to-day running of Polhill Garden Centre.

2. Apply a layer of mulch to preserve soil

As the temperature starts to drop, it's crucial to protect the soil from frost and extreme weather conditions. A layer of insulation is key, by way of mulch.

"Applying a layer of mulch around the base of your plants can provide insulation and help retain moisture in the soil," says Amy. "Organic mulches, such as shredded leaves or bark chips, also break down over time, enriching the soil with nutrients."

"The rate at which compost decomposes over the winter months slows down as the temperature cools, so you’ll want to give it a final boost ready for lush, fertile compost ready for use in spring. Turn it – get a garden fork and give it a good turn so that as much air is incorporated as possible."

Top tip: For added protection on chilly nights, Josh suggests: "Wrapping these plants with old bed linens or frost cloths." You could even use old towels in your garden for this; they're a great insulator.

Amy Stubbs

Amy is the Project and Development Manager at British Garden Centres and is the daughter of the founder Charles Stubbs. Amy started working on the nursery, before becoming Centre Manager of the flagship store, Brigg. She now oversees development works with the group and heads up the marketing team.

3. Relocate containers and potted plants

Consider moving tender plants indoors to a porch or greenhouse to limit the impact of the elements, where possible. "Because potted plants are more susceptible to frost damage, bring them indoors or to a covered space like a shed or garage," says Josh.

But where that's not possible, fear not, there are still steps you can take to protect your plants from frost.

When rearranging your plants, cluster them together so there's safety in numbers and look to move them to a more secluded area of the garden. "Safeguard potted plants by moving them to sheltered areas," Amy advises.

Look to move them to the side of the house or under an awning to provide a little extra shelter. Just make sure you flood your potted plants before bringing them inside; this will stop any unwanted hidden pests from taking over your home.

The bigger the grouping, the less exposed each plant is to the winter climate. Being huddled together, they can reduce the impact of strong winds whipping around each plant, for instance.

4. Insulate plant pots with bubble wrap

When it comes to your patio potted plants a layer of bubble wrap is the equivalent of use wearing the best winter coats– wrapping up warm to beat the cold.

"Potted plants should be grouped together and covered with blankets or bubble wrap to give additional insulation if they can't be brought indoors," says Josh. "Use bubble wrap or specialised container coverings to insulate pots in huge outdoor containers that are too heavy to relocate. By doing this, temperature fluctuations that might harm plant roots are reduced."

"Wrapping the pots in bubble wrap traps warm air around your potted plants," explains Jack Sutcliffe, co-founder of Power Sheds. "Cold weather, particularly frost, causes the water in plant cells to freeze, but bubble wrap can help them to survive harsh winter weather."

5. Wrap tree trunks

The wrapping process doesn't just stop at the pots, you also need to insulate and protect trunks on particularly vulnerable trunks – Banana plants being one example.

"Frost fractures can occur in young trees with thin bark," warns Josh. "Wrap the trunk with hessian or tree wrap to avoid this. The tree is shielded from potentially harmful excessive temperature swings by this covering."

6. Water in advance to retain heat in the soil

We know the best time to water lawns, but we're less likely to know when to water plants and gardens ahead of frost in the winter. However, the timing is extremely important during cold weather.

As Josh explains: "Make sure your plants get enough water before the first frost. A day or two before an expected frost, give your soil a thorough watering as moist soil holds heat better than dry soil."

Before warning: "On the other hand, refrain from watering plants in the late evening as they may freeze and become more damaged."

Knowing how to water your garden plants properly will put you in a good habit of knowing what different species in your garden will need a different amount of watering before the frost hits.

7. Avoid stepping on frosty lawns

Avoid the temptation to crunch over a beautifully frozen lawn because this is the worst lawn care mistake you can make during winter. "Frosty grass blades will be frozen from the inside out and are very brittle," warns gardening expert and director of Easy Garden Irrigation, Sean Lade.

"The crunching sound you hear while walking on it is the sound of grass blades breaking. Also, you’ll notice that the grass doesn’t feel springy like it does in spring and summer. When you tread on frozen grass, all the broken glass blades compact down and cover the grassroots. This prevents the roots from getting the water and oxygen your lawn needs to stay healthy."

Not stepping on the lawn is the easiest way to avoid concerning yourself with what to do with a yellow lawn come spring. "When spring comes around, you’ll see yellow patches of dead grass that will not grow back as quickly," says Sean. "If you are a proud owner of an immaculate lawn, I would suggest not treading on it. Even a small dog walking over it can snap the blades."

Sean Lade

Sean is an expert at Easy Garden Irrigation, an industry-leading BALI-accredited company. Sean holds in-depth expertise in gardening and horticulture, with a focus on designing efficient irrigation systems. His solutions grace gardens and nurseries across the UK, embodying an environmentally-conscious approach to water usage.

8. Check and ward off pests

Winter gardens are still prone to pest infestations that can damage plants ahead of next spring. "Check your plants for pests like aphids, spider mites, and scale insects before winter arrives," Josh advises. "These pests can weaken plants and increase their vulnerability to frost damage. To maintain the health of the plants, treat the infestations as needed."

"Winter is the perfect time for pests to invade garden plants and destroy growth opportunities when spring comes," Jack explains. For a natural remedy to deter pests, Jack suggests trying a dash of garlic to keep them away.

"The pungent smell of garlic will repel any pesky pests without damaging the plants. My top tip is to blend garlic with a little water to create a spray that will be easy to spread around the garden." You can also use simple washing-up liquid to wash pests away, which I've used on my bay tree recently due to a problem with scale insects (which you can see above).

You might also want to use some deterrents for keeping rats out of your garden and mice away from your home. Winter is when rodents will look for warm shelter and your house or shed will make the perfect new home.

FAQs

Does garden fleece protect plants from frost?

Protecting your garden from heavy rain and frost is extremely important once the weather starts to turn. It's particularly key to get ahead of the season and start frost protection earlier than you may think.

"Garden fleece protects plants from frost as the protective barrier created by the frost traps a layer of air around the plant to insulate it," says Richard Barker, horticulture expert and Commercial Director at LBS Horticulture.

"The fleece is porous, meaning that light, air and water can still reach the plant. For fleece to protect plants effectively, there should be a small gap between the fleece and the plant so that they are not directly touching," he adds.

Richard explains that this prevents frost from the fleece transferring onto the plant and stops moisture from being trapped underneath the fleece.

When should you start protecting your plants from frost?

Avoid making a winter gardening mistake and waiting too long to protect your plants from frost and cold temperatures. Timing is everything when it comes to this task.

"During the autumn months, the temperature can drop low enough to cause frost, as frost is simply frozen water and water freezes when the temperature falls below zero degrees Celsius," says Lucie. "However, ground frost can occur when the air temperature is above zero degrees."

"This is why you should monitor the weather forecasts and use a thermometer to measure the temperature within your garden, so that when the temperature reaches 4 degrees Celsius or less, you put protection in place to prevent frost damage," she adds.

Will cardboard boxes protect plants from frost?

There are many ways you can use cardboard in your garden to improve your plants; however, it's not the most recommended method of frost protection.

"Cardboard boxes can be used as a ‘quick fix’ to protect your plants from frost when you are caught out and need to use something you’re likely to have at home without needing to shop," starts Lucie Bradley, gardening expert at Easy Garden Irrigation.

"To be effective, you need to cover your vulnerable plant with the box late after whilst the sun is still out, so that the air inside the box can warm up before it becomes dark. You then need to make sure you remove the box in the morning as soon as the chance of frost is over, so your plant can get the sunlight it needs to remain healthy," she adds.

There are a few disadvantages to using cardboard, the first being that it completely covers your plants and puts them in the dark, away from all important sunlight.

"Secondly, cardboard is not waterproof, so if it rains, then the box will become unstable as it soaks in the water and could collapse, damaging the plant it’s covering. Finally, cardboard is only effective to protect plants from light frost - if the temperature drops below zero for long periods, the cardboard box will not provide sufficient protection," says Lucie.

Lucie Bradley

With over 28 years working in the garden industry, Lucie has been fortunate enough to spend every day speaking to both amateur and professional gardeners. Encouraged to garden since she was old enough to walk, she believes that you can never know everything about gardening, as it is constantly evolving.

What should I cover my plants with for frost?

There are a few things that garden experts recommend covering your plants with to protect them from harsh temperature drops and lethal frosts. The first being horticultural fleece, as mentioned previously.

"Whilst a sheet of horticultural fleece is good for laying over several plants or can be draped over single plants, you will also find ‘plant jackets’ on the market which use this fleece to make a shaped ‘jacket’ or ‘bag’ and incorporate a drawstring at the base, making them easy to secure in place. These are ideal for plants growing in pots, for hanging baskets or for small plants or shrubs in your garden borders," says Lucie.

Another traditional way to protect individual plants is to use a ‘bell cloche’, which has been used for centuries and was originally made from glass. You can still purchase glass cloches, such as this Bell cloche at Amazon, but there are more affordable, sturdy options now available.

"There is also the option of finding bell cloches made from plastic and incorporating vents in the top, which allows you to control humidity under the cloche more easily than a glass cloche does, which would need propping up on one side to allow fresh air to the plants it is protecting," explains Lucie.

When you've spent all year tending to your plot it is essential to do what you can to make your efforts fruitful for next year, to ensure your curated garden trends, best garden shrubs and carefully chosen bulbs continue to bloom next spring.