Houseplants in summer: heat, sun and holidays

In summer, plants grow fast and drink a lot. Sun through the glass, heatwaves and holidays are the three traps of the season: here's how to avoid them.

Updated on 6 October 2026

Water more, at the right time

In summer, plants grow at full speed and the heat dries the soil faster. It's the season when they drink the most: check the soil more often, twice a week for the thirstiest.

Water preferably in the morning or evening, with room-temperature water. Watering in the heat of the day partly evaporates before it reaches the roots. And even in summer, don't leave water in the saucer for more than half an hour: roots that sit in water end up rotting.

One exception: the cyclamen does everything the other way round. It's a winter plant that rests in summer, almost dry.

Beware of sun through the glass

A south- or west-facing window acts like a magnifying glass in summer. Even light-loving plants can burn there: the leaves get brown patches, dry to the touch, that won't go away. Move the plant back 3 ft (1 m), or draw a sheer curtain during the hottest hours.

Forest-floor plants are the most fragile, such as the Chinese evergreen, the cast iron plant, the rattlesnake plant, the calathea medallion, the calathea orbifolia and the peacock plant: keep them out of direct sun all summer.

During a heatwave

• Keep the house cool: shutters or curtains closed by day, windows open at night.
• Group your plants: together, they keep a little humidity around them.
• Mist the ones that like humid air, such as calatheas and ferns, but not succulents or hairy leaves, like those of the African violet.
• No fertiliser or repotting in the heat: the plant has enough to deal with.

Going on holiday without coming back to dry plants

The safest option is still someone who drops by to water. To make it easy for them, Xyléa's away mode prepares a clear list: which plant, when, and how much water. If no one can come, these steps help plants last one to two weeks:

1. The day before you leave, water thoroughly until water runs out of the drainage hole, then let it drain.
2. Move your plants away from windows, into the coolest room that's still bright.
3. Group them on a large tray filled with clay pebbles and a little water: the pots shouldn't sit in it.
4. For the thirstiest, a cotton wick can connect a container of water to the compost and moisten it bit by bit.

Some plants easily go two weeks without water, even in summer: the aloe vera, the bunny ears cactus, the golden barrel cactus, the African milk tree, the haworthia, the living stones, the mammillaria, the ponytail palm, the burro's tail, the snake plant, the cylindrical snake plant and the ZZ plant. They're the perfect companions for frequent travellers.

Putting plants on the balcony?

Many houseplants love spending summer outdoors, as long as they're protected. Put them out of the wind and the afternoon sun: even a sun lover isn't used to outdoor light. Keep an eye on watering, which can become daily, and check under the leaves regularly: outdoors, little bugs quickly find their way.

This advice is for houseplants in a temperate climate. Every home is different: trust your plant too, and the soil under your finger.