Worst mistakes gardeners can make in hot weather as heatwave arrives in UK

Daily Mirror

28-04-2025

With temperatures across the UK set to climb this week, there are things that gardeners should avoid doing to help keep their plants stay happy and healthy amid the warmer weather
With many parts of the UK currently basking in high temperatures and bright blue skies, a lot of Brits will be spending more time in their gardens and outdoor spaces. Whether it's relaxing in the shade with a good book or treating friends and family to the first barbecue of the season, rising temperatures make it tempting to spend more time outside.
The Met Office has forecast temperatures 'quite widely into the high teens, with a maximum of 25C possible in the southeast' for today, and things are set to get even hotter throughout the week. However, while the sunny skies might be a welcome shift in the weather, for gardeners it can lead to concerns about how to keep their space thriving despite the increasing temperatures.
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Luckily, some experts have shared the things gardeners should avoid when navigating the warmer weather…
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Watering at the wrong time
With soaring temperatures, it's natural for gardeners to worry about how much water their plants are getting. According to TV presenter and QVC gardening guru Mark Lane, timing is important when it comes to keeping your plants well watered in the heat. 'One of the worst mistakes you can make is to water your plants at the wrong time,' he previously said.
Mark recommends people water their plants earlier in the morning, between 5am and 9am, when the temperature is cooler, allowing less water to evaporate. Alternatively, watering in the late afternoon is another option as it will allow plants to 'dry off quickly which helps protect against the development of fungal diseases'.
However, watering should be avoided at night. Mark added: 'Watering at night can result in water pooling on the soil's surface, around the roots and on foliage which can lead to fungal growth, rot, insects and even the death of a plant.'
Overwatering your lawn
Like our plants, it can be tempting to keep our lawns well watered during hotter periods. That being said, watering the lawn too excessively can do more damage than good as it may lead to scorching.
Watering the lawn once a week should be ok, and mowing it once a week should work too. Gardening experts from Power Sheds have also advised people to adjust the blades on a mower with a higher setting to ensure the grass stems allow for maximum shade for the soil.
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When it comes to looking after plants, they added: 'The biggest risk to plants in high temperature is the soil drying out, your first line of defence against this should be to use a layer of mulch around plants to help the soil stay moist after watering. There are many different mulch materials gardeners can use during a heatwave, dry grass clippings from your lawn are a great option.'
Planting the wrong things
When the weather's good you might be tempted to put your gardening skills to the test, but you should think twice about what you're planting. Last year royal gardener Jack Stooks stressed the importance of timing when it came to planting certain shrubs.
'Ideally when you have excessively hot weather, you don't want to be planting trees and shrubs because when you plant these you will expose roots,' he said.
He added: 'You want to be planting these early on in the season or late in the season to get them established quite well.
'All in all, I wouldn't recommend planting anything in really hot weather because you have to really keep on top of it and really be cautious with what you are planting.'