Gardeners are being urged to place bottles of warm water in their garden this November – it actually makes perfect sense

We’ve had wind, rain, and even snow this week; there’s no denying that temperatures have suddenly plummeted, and if you worried about protecting your plants from the cold and frost, garden experts have revealed an unusual hack to keep them safe - and it involves putting bottles of warm water around your garden.

When it comes to protecting plants from frost and cold weather, your best bet is following the 4-degree rule for plants. This rule states that gardeners should start protecting their plants when the temperatures drop below 4°C.

Plant cells can become damaged or even destroyed by frost, which is why it is so important to protect your tender plants. One way to do this is by placing bottles of warm water near the plants you want to protect. Here’s how it works.

How to use bottles of warm water to protect plants

‘Placing two or three water bottles filled with warm water around plants can help quickly melt the frost off the top. Repeat this step morning and night to help your plants survive the frosty weather,’ explains Chris Bonnett from Gardening Express.

This hack works a bit like how a hot water bottle heats us when we’re cold. Placing a bottle of warm water near a vulnerable plant will warm the air around it as it slowly cools. And doing this first thing in the morning and at night will help protect your plants during the coldest parts of the day.

However, you should be mindful to only use water from the hot tap, rather than boiling water from the kettle, as boiling water could damage the container, as well as harming you or your plant if spilt.

‘Place this container of hot water close to your plant but not touching the foliage, as you don't want any condensation which forms on the outside surface of the container to touch your plant, as the leaves could then freeze,’ adds Lucie Bradley, garden and greenhouse expert at Easy Garden Irrigation.

‘So that the heat released by the water isn’t quickly lost as the air rises, cover the plant as well, using garden fleece (£8.59 at Amazon) for example, anchored securely around the base so there are no gaps to allow the heat to escape.’

While of course, there are some plants you should bring indoors before the first frost, it’s not practical or possible to put all your tender plants indoors or in a greenhouse, which is where this hack comes in handy.

Is this a good hack to use?

‘Although using warm water in this way will lift the temperature around your plant, it is only a temporary solution and not a long-term solution to keep plants protected,’ says Lucie.

‘However, it only works effectively when combined with covering your plants too to contain as much warmth as possible. It also needs you to replace the water when it has cooled, so although cost-effective, it can work out to be time-consuming.’

It is certainly an easy method, and only requires water from your tap and an old bottle from your recycling bin, but if you are looking for a longer-term solution, or don't fancy bracing the cold first thing in the morning, there are better alternatives. From planting cold-loving plants in the first place to placing a thick layer of mulch around your plants, there are plenty of ways to keep your plants safe.

‘For containers too large to relocate, insulation becomes essential. Wrapping pots in a layer of straw or bubble wrap helps reduce heat loss, and adding a fleece cover gives an extra barrier against cold snaps,’ says Amber Tunney, Horticultural Specialist at Cherry Lane Garden Centres.

‘Larger in-ground plants may also benefit from physical shielding. Drive a few stakes into the soil around vulnerable specimens and wrap horticultural fleece around the frame to create a simple protective jacket. For individual plants that need a little extra help within a border, a homemade cloche can be invaluable: shape a cylinder of chicken wire, fill it with leaves or straw, and secure it over the plant to provide both insulation and airflow.’

If the sudden cold snap has left you unprepared to protect your tender plants, can you see yourself using bottles of warm water to keep them safe?