How to care for houseplants in a heatwave: 5 ways to protect plants from extreme temperatures
When the heat arrives, it's important to give your indoor plants a little TLC so they can thrive and not wither in the sun
When the hot weather hits, it's all too easy to focus on your outdoor plants and forget that your houseplants need some more attention too.
Similar to how you'd keep your plants alive whilst you're on holiday, they need extra care when surprisingly high temperatures come to the UK. Dryer air and warmer homes lead to extra thirsty plants that can be susceptible to leaf scorching, among other things.
How to care for houseplants in a heatwave: expert advice
It's all well and good using houseplants to keep a room cool in summer, but if you don't provide them the added nutrients and care they need in the heat, they won't be much help.
So while you may have mastered how to care for your houseplants in winter, here's everything you'll need to know to help them survive the hot summer months.
1. Avoid sun scorching
Giving your houseplants too much sun, even through winter, is a common houseplant mistake, but during summer, it can be particularly damaging for your plants.
"Treat plants like people - you wouldn’t sit in full sun midday, so shift them into indirect light or shade zones to prevent scorching," says Connor Towning, lead horticultural expert at Beards & Daisies.
He recommends moving plants away from direct afternoon sun, especially if they're near south- or west-facing windows. You can also use light blinds or sheer curtains to avoid sunburnt plants.
With five years of experience in the plant industry, Connor Towning plays an essential role as lead horticulturist at Beards & Daisies. His passion for plant science drives him to collaborate closely with growers, ensuring the best varieties and latest trending plants are selected. His hands-on approach guarantees that every plant meets the highest quality standards before reaching your home.
2. Regularly check soil moisture
If you struggle with mastering your houseplant watering routine, then making it a habit to check your plant's soil can be a huge help. Especially when you're experiencing high temperatures, as your plants are more likely to need watering much more often.
Luke Newnes, gardening specialist and member of the Interior Squad at Hillarys, echoes this: "Check soil moisture frequently, as houseplants may need more frequent watering during extreme heat."
RRP: £23.49 | The long, thin spout on this watering can makes it easy to get a good pour into any of my plant pots, and the spray bottle is a priceless addition for summer watering.
Joining the Hillarys Interior Squad, Luke—also known as The Pink Gardener—is a new-build gardening specialist and content creator. With a talent for transforming outdoor spaces, he shares expert gardening tips and inspiration. When he’s not making digital content, Luke works at a garden centre, where he continues to share his knowledge and enthusiasm for gardening and the outdoors.
3. Increase humidity
During winter, you might call on plants to help with condensation and humidity, but when the dry weather comes, you may have to help them out with a humidifier.
"Group humidity-loving plants together, use pebble trays, or lightly mist them in the morning. It protects against crisp leaf edges," recommends Connor.
The hot weather, along with fans and even AC, can stress your houseplants, causing them to wither or die prematurely.
4. Adjust feeding
Many forget how important feeding is when caring for their indoor plants. Not only do plants need some extra nutrients from time to time, but their need for them changes throughout the seasons.
"Feed in the early morning or evening with a diluted houseplant fertiliser to let plants absorb nutrients before heat kicks in," says Connor.
Feeding them in the hottest part of the day can burn roots, so it's key to get your timing right.
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5. Rotate your plants
Warmer weather will encourage your plants to grow more, but it's important you rotate your plants in the sun so they're evenly hit.
Connor echoes this, saying you'll need to turn round larger plants weekly, as this will help balance growth and also prevent one side from burning or wilting.
Just make sure to keep track of which plants you've rotated, or you might accidentally forget leaving them to be damaged by too much sun.
FAQs
How hot is too hot for indoor plants?
Sometimes when we're too busy trying to keep ourselves cool in the heat, we don't think about how the rising temperatures can affect the plants in our homes. And just like how it can feel too hot for us, our plants can reach a limit, too.
"In glazed rooms, temperatures can exceed 30°C quickly, which is too hot for most houseplants. Aim to keep 20–26°C, and take action once you hit 27–28°C by shading and ventilating. In garden rooms and sunlit spaces, including pods, an office or a bar, I watch the thermometer and adjust blinds, vents and fans before the room peaks," explains Angus Mackintosh, Director of Designer Garden Rooms.
Do indoor plants need more water in hot weather?
In the same way, you might wonder if your outdoor plants need watering more frequently in hot weather; you might be questioning the same for your indoor plants.
"Yes, soil dries faster in sun-facing garden rooms. Check moisture daily and water when the top 2–3 cm of compost is dry, not by the calendar," starts Angus.
"Morning is best, so plants drink before heat builds, and always water thoroughly, then allow excess to drain so saucers don’t hold standing water. In my work, I’ve noticed that consistent soaking and full drainage give better resilience than frequent light sips," he adds.
Should you be unsure if your plant needs a good watering, you can always check if the soil feels dry, and if so, it's ready for a drink.
Will plants recover from heat stress?
If you've forgotten to water your plant a few too many times, you might be left with a peace lily with browning leaves. Even if your plant has started to show signs of heat stress, there's hope for it yet.
"Usually, provided you lower the temperature and light intensity within a day or two. Leaves that are scorched or translucent won’t revert, so expect some cosmetic damage, but the plant should push healthy new growth once conditions stabilise. Keep it steady for a couple of weeks and avoid extra stress while it rebuilds energy," explains Angus.
How to bring a plant back to life after overheating?
So, how can you do it? How can you bring your beloved plant back from the brink of death after suffering from overheating?
"First, cool the environment by pulling blinds or curtains, adding shade film if you have it, opening windows or roof vents for cross-ventilation, and running a fan for gentle airflow," begins Angus.
"Next, adjust placement by moving plants 1–2 m back from south or south-west glazing and use sheer curtains to diffuse the sun. Water thoroughly until excess runs from the drainage holes, then drain the saucer, and don’t feed until you see new growth," he continues.
"Trim only the worst scorched leaves so the plant can focus on recovery. Resume normal care once growth is steady and temperatures are back in the 20–26°C range," Angus finishes.
Should you be one of those plant parents who don't have much time on their hands and can't give even more attention to their houseplant collection during summer, we recommend picking the easiest plants to keep alive. They're low maintenance and sturdy, so even if you forget to water them, they'll be able to bounce back pretty quickly.
