Can you water grass in the sun? Yes, but it's better to pick the right time of day, say lawn experts

During a heatwave, our gardens are under a little extra pressure, so many of us will be wondering how to care for them in the heat. But can you water grass in the sun?

After spending time and energy on your lawn ideas, it's important to keep your grass healthy during the hottest days of the year. Knowing how often you should water your garden in hot weather can turn into a guessing game, which is why we've asked lawn experts for their verdict on watering grass in the sun.

'Water is an essential element of your lawn’s health and should not be neglected, especially in the summer heat,' says Steve Taylor, lawn guru at GreenThumb. 'Grass is made up of 85% water, so maintaining a robust water management system is crucial.'

Can you water grass in the sun?

Even the best lawn care tips are tested during the height of summer, and it's difficult to navigate the dos and don'ts of watering the garden under the blazing heat.

It's important to keep your lawn hydrated, though. 'Proper hydration strengthens the root system, improving the lawn’s ability to withstand stress factors such as heat, foot traffic and lawn disease,' says Cheryl Harper, Managing Director of Greensleeves Lawn Care. 'Additionally, water helps cool the grass blades and soil, reducing the impact of prolonged high temperatures.'

But can you water grass in the sun?

'Firstly, if your lawn is well established then it's unlikely to need constant watering, even in very hot weather,' says Henry Bartlam, founder of Dig. 'However, if you need to water it (especially if it's a new lawn from seed or turf) then you can water it in hot weather.

'But, you should do so when it's not in the full glare of the sun. It's best to water when the sun is not as strong, and the water is less likely to evaporate.'

Cheryl Harper

Cheryl Harper is the managing director of Greensleeves Lawn Care.

Established in 1998, Greensleeves Lawn Care is a UK-wide lawn care business with over 100 locations.

It's also important to keep in mind that watering the garden in the sun can be inefficient. 'In particularly hot weather, or during a heatwave or drought, watering during the day when the sun is at its hottest will cause most of the water to evaporate,' says Chris McIlroy, lawn expert at The Grass People. 'This means your time and resources will be wasted and the water won’t soak into the soil.'

Now that we've established that you can water your grass in the sun, but that you should pick the right time of day, when exactly should we be watering our lawns?

Chris McIlroy

Chris is the technical product lead and in-house lawn seed expert for The Grass People, a grass seed company that champion their expert lead advice and high-quality seed. His advice is focused on sowing, mowing, and maintaining a perfect lawn, and how to overcome any lawn issues homeowners face.

When is the best time to water your grass?

Experts advise that certain times of day will allow you to get the most out of your watering sessions.

'The best time of the day to water your grass is early in the evening, ideally between 6pm and 8pm,' says Steve from GreenThumb. 'Watering during these hours allows the grass to absorb moisture effectively overnight when there is no evaporation from the sun.'

Just be careful not to water your grass too late. 'Wet grass overnight can promote fungal and bacterial growth,' says Cheryl from Greensleeves.

If you'd prefer to water your grass in the morning, that works, too. 'Watering your lawn in the morning means the temperatures are cool enough for the water to soak into the soil without the risk of evaporation, and your lawn will be hydrated for the day ahead,' adds Chris from The Grass People.

So, during particularly sunny periods, watering your grass during the cooler parts of the day is key.

How much should you water grass in hot weather?

Now we know that watering grass in the sun is possible, but that it's best to water out during the cooler parts of the day, we're wondering how often we should be soaking our lawns.

Although it can be tempting to scale up the watering sessions during a heatwave, it's important not to overdo it.

'Don't water your lawn too frequently,' advises Sean Lade, director of Easy Garden Irrigation. 'Once or twice a week is more than enough. We want the soil to be dry and the grass to be thirsty before we water it. Ideally, the grass would just be starting to yellow and have slightly lost its spring (staying flat after it has been stepped on rather than bouncing back).'

Chris from The Grass People agrees: 'You should water heavily and infrequently. The aim is to develop a good root system. The grassroots will search for water by pushing down, so you can allow the grass to get a little thirsty sometimes. In a drought, you might want to up this to watering twice daily, or invest in a sprinkler.'

So, the verdict? When watering in hot weather, it's important to give your grass a quality soak rather than regular sprinkles.

Watering essentials

FAQs

Can you water new turf in the sun?

Caring for new turf can be tricky during bouts of hot weather, especially when you've put time and effort into establishing the new grass.

'A new turf needs to be kept moist in order to establish itself and for seeds to germinate,' says Chris from The Grass People. 'After sowing your seeds, it’s crucial to keep the soil moist but not waterlogged. The sun can be harsh on new turfs, so consider watering lightly and often to maintain moisture levels.'

Is it OK to cut grass in the sun?

Although it's tempting to stick to your regular mowing routine throughout the summer, dialling it back during hot weather can actually help maintain your lawn's health.

'Mowing can cause stress to your grass, so it’s often best to leave your lawn to grow a little longer in these conditions,' explains Jonathan Hill, sales director at Rolawn.

'The mower blade should always be sharp and the cutting height should be increased during dry conditions. This helps trap valuable moisture, limit evaporation and encourage deeper roots to form, which improves drought tolerance overall.'

So, can you water grass in the sun? You can, but it's better to wait until the cooler parts of the day, in the morning or evening, to make watering sessions the most efficient they can be and ensure your grass gets the hydration it needs.