5 popular garden plants that suffer most during a heatwave – and how to save them

Pay extra attention to these varieties during summer

By Wanda SachsPublished: 09 July 2026

red roses and blue hortensia (hydrangea hortensia) in a flower bed.

Federico Magonio//Getty Images

Summer brings plenty of nourishing sunshine, helping gardens burst into bloom, but it's also a precarious time for plants. Too much heat can quickly become a problem, putting them under stress – and some more than others.

'While many garden plants can cope with periods of warm weather, prolonged heatwaves can put extra stress on varieties that prefer cooler, moist conditions,' says Dobbies' plant buyer, Nigel Lawton.

'Keeping an eye out for the early signs of heat stress and making a few simple adjustments can help your garden continue to thrive throughout the summer.'

Read on to discover five popular garden plants that need extra attention during a heatwave.

Hydrangea

Nadya So//Getty Images

These blowsy beauties are among the plants most vulnerable during a heatwave.

'Hydrangeas are particularly susceptible to hot weather because of their large leaves and flowers, which lose moisture quickly,' says Nigel.

Stress signs: Drooping leaves, wilting blooms and dry soil around the base of the plant are all telltale signs that it's struggling.

How to help: Water deeply in the early morning or evening when temperatures are cooler, ensuring the water reaches the roots rather than evaporating from the surface.

Applying a layer of mulch around the base of the plant will also help the soil retain moisture for longer.

Acer

mtreasure//Getty Images

Their shallow root systems and delicate foliage mean that these ornamental trees need additional TLC when it's sweltering.

'During hot weather, the leaves can lose moisture faster than the roots can take it in from the soil, and as their roots sit close to the soil surface, they are sensitive to sudden changes in temperature,' explains Richard Barker of LBS Horticulture.

Stress signs: Your acer is struggling if you spot that its leaves turn brown on the edges, curl inwards or start drooping.

How to help: In a heatwave, move potted acers into a shaded area that is sheltered from winds. Water the plant thoroughly in the morning at the base, and container plants may need watering twice a day.

If you cannot move your plant, provide shade using garden shade cloths.

Advertisement - Continue Reading Below

Rose

Photos by R A Kearton//Getty Images

Despite being sun worshippers, these classic British garden flowers start to struggle when it gets too hot.

'This is because their leaves lose moisture quickly through transpiration, and this can also weaken the plant's ability to photosynthesise and take up nutrients,' Richard explains.

Stress signs: A stressed rose's flowers will start to droop, shrivel and fade, and its foliage may even turn yellow, curl and wilt.

How to help: Rose bushes should be covered during the hottest part of the day, and this can then be removed when temperatures drop in the evening.

Check the soil moisture of roses daily, and water deeply to ensure that their root ball is saturated.

Fern

Feifei Cui-Paoluzzo//Getty Images

A standout at this year's RHS Chelsea Flower Show, ferns don't appreciate prolonged sun exposure.

Ferns are one of the first plants to struggle during prolonged spells of hot, dry weather,' says Nigel. That's because these shade dwellers prefer cool, damp environments.

Stress signs: Brown, crispy fronds and wilting foliage are clear signs they're becoming stressed.

How to help: Keep the soil consistently moist and, where possible, move potted ferns into a shaded spot during the hottest part of the day.

For garden-planted ferns, watering thoroughly and adding mulch around the base will help conserve moisture.

Advertisement - Continue Reading Below

Fuchsia

phanasitti//Getty Images

These beautiful blooms may also need some extra attention during the year's hottest months.

'Fuchsia are native to shaded, humid forests and grow at higher altitudes where the air is cooler, meaning they do not like hot, dry weather,' Richard explains.

'They have delicate root systems that can bake in plastic pots in the heat, and like many other plants that are vulnerable to the heat their leaves lose water faster than their roots can pull it from the soil.'

Stress signs: Look out for shrivelled flowers, dropped flower buds, scorched leaf and petal edges, and light or discoloured areas on leaves where they have been scorched in sunlight.

How to help: Place plants in darker or thin plastic pots inside another larger, light coloured container to stop the roots from baking in the sun.

Potted plants should also be moved to a more shaded and sheltered spot, and watered thoroughly in the morning.

Follow House Beautiful on Instagram, TikTok and Pinterest