How to protect potted plants in a heatwave – 7 expert tips to stop containers drying out when temperatures soar

As anyone who has spent a summer nurturing a container display will know, potted plants are often the first casualties when a heatwave hits. Unlike plants growing in borders, they have a limited amount of soil around their roots, meaning they dry out much faster and their roots can quickly overheat. I've definitely noticed that in my own garden anyway.

If you're wondering how to keep your garden or patio cool in a heatwave, protecting your container garden is probably high on your list, especially if you're dealing with wilted foliage, scorched leaf edges and drooping blooms. So I've asked the experts how to spot the signs your plants are suffering from heat stress and the tricks they have up their sleeves to stop them reaching that stage.

From creating shade to mulching and keeping roots cool, these are the expert-approved tips to help your containers cope with soaring temperatures and keep your garden looking its best throughout the summer.

Latest Videos From

Watch full video here:

'Heatwaves can be tough on potted plants because they dry out so much faster than anything planted in the ground,' says Jo McGarry, luxury garden design expert at Caragh Nurseries.

1. Move pots outside of the strongest sun

One of the first things I do when a heatwave is forecast is move smaller containers into a more sheltered position. Even shifting them a few metres can reduce the amount of intense afternoon sunshine they receive.

Lucie Bradley, gardening expert at Easy Garden Irrigation, recommends relocating pots to a north or east-facing wall or placing them beneath trees or larger shrubs where they'll benefit from natural shade.

Jo agrees that reducing exposure to the hottest part of the day can have a dramatic effect.

'If delicate plants are starting to look a little frazzled, creating some temporary shade can make a huge difference,' explains Jo. 'A small parasol, a shade sail like an IOAOI garden shade sail from Amazon, or simply moving pots somewhere that gets a break from the afternoon sun can help take the edge off during the hottest hours.'

Plant shade picks

2. Mulch your pots to lock in moisture

Of all the ways to protect potted plants in a heatwave, adding mulch is probably one of the simplest. I've been using RocketGro Magic Mulch, which you can pick up for £14.68 from Amazon, in my own pots recently, and I've found the compost stays noticeably moist for longer between waterings.

Jo is also a strong advocate of mulching containers during hot weather.

'One of the easiest ways to help is by adding a layer of mulch to the top of the compost,' says Jo. 'Bark, gravel or even leftover compost will help hold onto moisture for longer and stop the soil from baking in the sun.'

Lucie recommends applying a generous 5-7 cm layer of the type of mulch of your choice, such as coco coir like Coco&Coir's from Amazon, mini bark chippings or minierlised straw mulch, to shade the soil and slow evaporation.

Shop for top-rated mulch

3. Water plants deeply and at the right time

When it comes to watering plants in hot weather, timing matters just as much as quantity. Rather than giving containers frequent light drinks, I try to water thoroughly first thing in the morning before temperatures rise.

'It's worth giving plants a really deep drink first thing in the morning or later in the evening, rather than a quick splash during the hottest part of the day,' says Jo.

Deep watering encourages roots to grow lower into the compost where moisture remains available for longer.

Plant pot watering essentials

4. Group pots together

I've always grouped containers, not just because I think it looks good, but also because it makes watering easier, but it turns out it can also help protect plants during a heatwave.

According to Lucie, clustering pots creates a microclimate, with larger plants shading smaller ones while the moisture released from the foliage helps increase humidity around the display.

Jo says grouping containers can also reduce moisture loss. 'Grouping pots together can help create a slightly cooler, more sheltered environment and reduce moisture loss,' she explains.

5. Protect pots and roots from overheating

One tip I hadn't even considered until the experts mentioned it is just how hot the actual container can become. Dark-coloured pots, metal planters and unsealed terracotta can absorb huge amounts of heat during a heatwave, explains Jo.

'Moving them to a cooler spot or shielding the sides of the container can help prevent roots from overheating,' she adds.

Lucie recommends wrapping containers with hessian, reflective materials like plant reflective film from Amazon or placing smaller pots inside larger, light-coloured planters to provide a little extra insulation.

6. Lift pots using pot feet

Pot feet might seem like a small addition, but they can make a surprising difference during hot weather.

Lucie explains that elevating containers improves airflow beneath the pot, helping keep roots cooler while also improving drainage after watering.

You don't necessarily need specialist pot feet either. Bricks, stones, wine corks, or bottle caps can all work for smaller containers.

Pot feet picks

7. Use watering spikes for extra support

If you're worried about your containers drying out while you're at work or away for a few days, watering spikes are well worth considering.

'Watering spikes are another handy solution during hot spells, particularly for anyone spending long days away from home or heading off for a few days,' says Jo. 'They release water slowly and steadily, helping compost stay moist for longer.'

Lucie recommends terracotta irrigation spikes, like these from Amazon, or watering cones that slowly deliver water directly to the root zone while reducing evaporation.

Shop these watering spikes

So, there you have it! Heatwaves are always a challenge for container gardeners, but a few preventative measures can make a huge difference.

As Jo puts it: 'The key is keeping a close eye on potted plants during the very hot weather. Conditions can change surprisingly quickly in a container, but a few simple adjustments can go a long way towards keeping plants healthy until temperatures return to normal.'

Stay cool!