7 things you should never do when gardening in hot weather

Experts reveal the things you should and shouldn't be doing during a heatwave to keep your garden thriving

Slatted fence with plant pots and watering can hanging from it
(Image credit: Future PLC)

Temperatures are set to rocket up past 30 degrees this week, meaning much of our attention will be turning to our gardens. However, while our gardens might love a spot of sunshine, gardening in hot weather should be undertaken carefully. The wrong move could make the difference between preserving and protecting our beloved garden ideas and destroying them. 

While there will be those that immediately think of bathing in a paddling pool and BBQs the vast majority of gardeners will be concerned for their lawn ideas and floral borders. Hot weather gardening mistakes can trip many gardeners up, throwing up questions such as when should you water plants in hot weather and is it safe to do any planting? 

So we've rounded up expert top tips on the mistakes to avoid, and what to do instead to keep our outdoor spaces looking exceptional despite the heat.

Mistakes to avoid when gardening in hot weather

1. Over-watering plants during a heatwave

Slatted fence with plant pots and watering can hanging from it

(Image credit: Future PLC)

Many people will be wondering about watering a garden in hot weather, however, less is definitely more during a heatwave. Overwatering is a common mistake to make when the mercury starts to soar. 

'Don’t give your plants a daily light sprinkling of water. Better to give them a good soak every couple of days (especially in warmer weather) than a quick splash every day,' explains  Henry Bartlam, founder of Dig.

'There is no precise science to this, but if the soil looks nice and damp, and doesn’t dry out quickly, you’ve probably done a good job. 

'Be careful not to overwater and saturate the soil though - not only could this eventually damage the plants, but also wastes valuable water. The general rule of thumb is that if you touch the soil and it feels damp, you can probably leave it a day or two… but probably not a week.'

2. Watering plants during the day

'One of the worst mistakes you can make is to water your plants at the wrong time,' says presenter and QVC gardening expert Mark Lane. 'The best time is early in the morning when the outdoor temperature is cooler, between 5:00 and 9:00 am, resulting in less water lost to evaporation.'

'Early morning is preferable to late evening watering as the plant can dry off quickly which helps protect against the development of fungal diseases. 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.'

3. Planting tender plants in hot weather

Navy fence panels with potting table

(Image credit: Future PLC / Joanna Henderson)

While not a huge blunder, planting up during a heatwave is best avoided to give your new plants the best chance of survival. 'It's not ideal to be planting things when it's so hot - especially if they are small, tender plants,' says Henry Bartlam, founder of Dig. 'But you can still do so if you ensure the soil is well prepared and moist and that you avoid planting when the sun is at its strongest. 

'The most important thing to do as soon as you have planted up is to give everything a good water.'

Alternatively, if you are determined to give your garden a facelift this weekend consider opting for drought-resistance plants such as ornamental grasses in your garden landscaping ideas.

4. Forgetting to shade soil from the sun

The temperature of your soil might be the last thing your thought to cover when considering garden shade ideas during a heatwave, however if the temperature rises too much it can impede on the plants ability to take on water and nutrients. 

'It is important to shield your soil from the sun where possible,' points out Sean Lade, director of Easy Garden Irrigation. 'The best way to do this is to spread a layer of mulch over your soil to shield it from the sun. This will help keep it cooler and prevents moisture from evaporating.'

'Roughly a 2-inch layer is best and this will ensure that your plants will be happy throughout the hot weather. '

5. Ignoring incoming weeds

Plant pots on table

(Image credit: Future PLC / Andrew Woods)

Summer is the best time to tackle weeds, and there's not better time than in a heatwave when everything else should be left alone and weeds will be thriving. 

'The fight against weeds is real,' says Sean Lade at Easy Garden Irrigation. 'During the summer season is when weeds proliferate, so it is crucial that you do not give up the good fight to keep them at bay. Otherwise, you'll be overrun with weeds before you know it.'

'Pull them up with their roots and weeds are easiest to pull when they are young and small and have less chance of spreading seeds. You will more than likely need to use a hoe to pull up established weeds completely, so it may be worth investing in one if you haven’t already.'

6. Panicking if your lawn turns brown

A brown lawn might have you running for your hose. However, the experts assure us not to panic if you see your lawn turning brown on a hot day, as it should return to normal when the temperature drop if your lawn is well established. 

'Trying to keep your lawn green during longer spells of hot, dry weather can be an unnecessary waste of time, effort and water. During a heatwave your lawn might dull in colour or turn brown and become dormant, but don’t worry, if the turf is good quality it should recover quickly when rain falls, as it inevitably will,' explains Jonathan Hill, Sales Director, Rolawn.

You can consider investing in a smart irrigation system for the whole garden. This should take any worry out of keeping on top of watering best practice during a heatwave. 

7. Cutting your lawn too short

lawn with grass and shed with white door and window

(Image credit: Future PLC/David Giles)

When getting out your best lawn mower this summer, don't leave the setting at its lowest. 'Many people may not consider this small tweak that will benefit your garden in warmer weather conditions, which is to change the height of the blades on the lawnmower,' says Sean Lade at Easy Garden Irrigation. 

'Changing the blade to leave grass longer when cutting the lawn will provide shade for the soil to keep it as moist as possible and prevent the soil from drying out. Remember to mow your grass frequently and when it is dry throughout the summer too.'


Tamara was Ideal Home's Digital Editor before joining the Woman & Home team in 2022. She has spent the last 15 years working with the style teams at Country Homes & Interiors and Ideal Home, both now at Future PLC. It’s with these award wining interiors teams that she's honed her skills and passion for shopping, styling and writing. Tamara is always ahead of the curve when it comes to interiors trends – and is great at seeking out designer dupes on the high street. 

With contributions from