Extreme heat can put a garden under enormous stress. As temperatures are set to hit a record-breaking 39°C this week, many gardeners might wonder (indeed, worry) what they can do to protect their hard work from simply withering away in the heat.
It might be freeing (although, admittedly, a little depressing) to know that, when it's this hot, you probably won't succeed in saving all of your garden flora.
In fact, trying frantically to keep up with care for every single plant can result none of them getting what it really needs, and water is precious, so it's important to use it wisely. Some gardening jobs can also actively distress plants that are already suffering from heat stress.
What you need in times like this is a gardening triage list: a definitive agenda of the tasks that are actually essential and those that can be left for when temperatures are back at humane levels.
1. Don't: Water or mow your lawn
One of the first things to let go of is what's arguably the pride and joy of many homeowners. "Don't bother watering you lawn," garden designer and RHS Chelsea Flower Show medallist Matthew Wilson shared in a reel on Instagram. "It's a terrible waste of water."
"Your lawn will go brown – it's fine," he stressed. "Ours goes brown every year; it will come back and be green again next year."
Mowing is also a no-no during a heatwave. As Nick Ee at home improvement retailer BLACK + DECKER explains, cutting the grass puts significant stress on a lawn when temperatures are higher than 25°C. "When grass is battling high temperatures and a lack of moisture, cutting it can further weaken the plant and severely hinder its ability to recover," he says.
Taking a week off from mowing will probably sound appealing anyway in this heat, but if you still must, tackle your lawn in the early mornings or later in the evenings, when it's a little cooler, and raise your cutting height to at least 1cm above your usual setting.
2. Do: Add mulch layers
Water is a precious resource when it's hot. One way to make it last is to add mulching to beds and borders. "Adding a generous layer of mulch at the base of your plants will help improve the soil structure and will allow the soil to retain water for longer," says Chris Bonnet, horticulturalist and founder of online garden centre Gardening Express.
3. Don't: Use fertilisers
A gardening task you'll want to avoid at all costs right now is feeding. "Stay away from fertilising the lawn or plants during a heatwave," says Chris. "Not only can they burn plants but fertilisers encourage new growth which can stress plants and cause them more harm than good."
4. Do: Water potted plants rigorously
Most plants need extra moisture when it's sweltering, but there's one group that requires gardeners to be a particularly attentive.
"A lot of people make the mistake of treating their container plants the same as other plants in the garden, but the truth is they require a different kind of care," Chris says. "Pots dry out much quicker, so it’s important you water them more during dry spells."
This advice was also echoed by famous gardener and TV presenter Monty Don, who stressed the importance of keeping containers hydrated.
"The best time to water your container is early morning before the sun warms up," he said. "If you can't get it done early in the morning, don't do it during the middle of the day – wait until the evening. Basically, when it's cool." The same goes for non-container plants as well.
5. Don't: Prune or weed
Many flowers and shrubs benefit from a good pruning session in June, but things change when temperatures are in the high thirties. "If possible, try to avoid pruning any plants during extreme heat," Chris says. "Unnecessary disturbance can stress plants more."
The same goes for removing weeds, which grow like, well, weeds in this weather. But instead of reaching for your joint scrapers and hoes, Matthew advises to simply let them be for now.
"If you've got weeds in your border, don't be tempted to pull them out, don't be tempted to hoe," he urges. "Because that will disturb the soil surface and that makes it more prone to more moisture loss."
This week, focus on the essential tasks and pick up your regular gardening schedule again when the heatwave has passed.
Summer gardening edit
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Wanda Sachs is the Multiplatform Writer for Country Living and House Beautiful, exploring the latest in gardening, wildlife and sustainable living alongside interiors and property. She is particularly interested in human-interest stories, the intersection of design and pop culture, and the evolving relationship between urban and rural life. Previously, she served as Associate Editor at The Berliner in Berlin, where she reported on culture and fashion. Wanda studied English and German at the Goethe University Frankfurt and Exeter University.
