Can you water grass in the sun? The experts tell us all

As the summer sun starts beating down, our gardens can take something of a hit. But what are you meant to do - can you water grass in the sun? Or is that a myth?

Looking after lawn ideas in the warmer months can be a bit of a minefield, so we've spoken to the experts to find out exactly what we should - and shouldn't - be doing to our grass.

And while all the advice should help you care for your garden, remember that you needn't stress too much. 'During a heatwave your lawn might dull in colour or turn brown and become dormant, but don’t worry,' says Jonathan Hill, Sales Director, Rolawn. 'If the turf is good quality it should recover quickly when rain falls, as it inevitably will.'

Can you water grass in the sun?

One of the most commonly asked questions in every heatwave is can you water grass in the sun? And for good reason. We've all heard mixed messages about what lawn care tips you should actually be paying attention to in order keep your grass healthy and happy.

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

So there we have it - try and water your grass out of direct or very strong sun. But is there a specific time of day this works best for?

When is the best time to water your grass?

There are certain times of day when the experts advise is best to water your lawn to keep the grass in as good a condition as possible.

'The best time of day to water your lawn is either early morning or late evening to ensure you don't lose water to evaporation,' explains Sean Lade, Director, Easy Garden Irrigation. 'This helps prevent wasting water and helps the water to penetrate deeper.'

'Although make sure you're not watering too late as the grass will remain wet, as the temperature drops overnight.'

How much should you water grass in hot weather?

We now know the answer to can you water grass in the sun is that it's best to water out of direct bright sun, ideally early morning or late evening. But is there a rule of thumb as to how much water you should be using? Well, there are a few schools of thought here.

'Don't water your lawn too frequently,' advises Sean from 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. The grass would ideally just start to have a yellow tinge and has slightly lost its spring (stays flat after it has been stepped on rather than bouncing back).'

'If you have a BBQ at the weekend and you want to impress, water the before the big event to get it looking its best,' Sean suggests. 'Try to stick to a consistent schedule for the best results.'

When watering in hot weather, it's important to have a quality soak rather than regular sprinkles.

'An occasional good soaking is more effective than light daily watering which will not reach far below the surface and will only encourage shallow root growth,' says Jonathan from Rolawn. 'Try to water evenly, ensuring the whole lawn gets attention, and avoid watering in a breeze that might blow water off course.'

'Soak the lawn,' agrees Sean. 'Apply an inch or two (25-50mm) of water to the lawn so it can sink down beyond the grass root zone. If you have shaded areas that don't get much sun, don't soak them as much. If the lawn is so dry that the water starts to run off, water in stages across a couple of days.'

How do you look after a lawn in hot weather?

Aside from can you water grass in the sun, when and how much, is there anything else we need to know to keep our lawns ship-shape even through a heatwave?

Of course! One thing to note is that you should try and avoid mowing your grass. 'Mowing can actually cause stress to your grass so it’s often best to leave your lawn to grow a little longer in these conditions,' explains Jonathan from Rolawn. 'The mower blade should always be sharp and the cutting height should be increased during dry conditions. This helps to trap valuable moisture, limiting evaporation and encouraging deeper roots to grow, which improves drought tolerance overall.'

Additionally, dial back on fertilising. 'Unless you are committed to watering your lawn every day, we’d recommend avoiding granular feeds for a few days,' says Carlos Real, Managing Director, TotalLawn. 'That’s because the fertiliser can burn your lawn in the hot weather if it isn’t properly watered, so save the feed until after the heatwave.'

Finally, try and use rainwater when possible - and not just because it's a great example of budget garden ideas. 'Rainwater has higher levels of nitrogen which boosts growth, and you can avoid the dreaded hosepipe ban if you're able to do this,' recommends Sean from Easy Garden Irrigation. 

'It is important to consider that if you plan to use rainwater to keep your garden watered during periods of drought, you will want to have an extra-large water butt or rainwater harvester to ensure you have enough water to last for a couple of weeks.'

Can you water plants in the sun?

Aside from wondering can you water grass in the sun - what about plants and flowers? Luckily, it's very similar to looking after a lawn.

'When it comes to watering your plants, there are some key points to consider,' explains Marcus Eyles, Horticultural Director, Dobbies. 'Avoid watering during the day and instead, give your plants a drink early in the morning or in the cool of the evening. Water with the hose on a trickle, putting it directly on the soil and give the plants a good soak, ensuring you don’t water directly onto foliage or flowers.'

'Adding watering granules to the compost will help new plants to hold water in the warmer months,' continues Marcus. 'For larger borders and garden edging ideas, installing a soaker or sprinkler hose will help keep on top of watering. And installing a water timer to automate your watering if you’re away during the summer will keep your plants hydrated.'

'Remember the basics and don’t over water your plants - although it's tempting,' adds Martine Le Gassick, Creative Director, Stark & Greensmith. 'In a heatwave, water your plants a day or two in advance, and then not again until the soil begins to dry out. Add some reflective mulch like tree bark or grass cuttings to your planters - mulch protects the roots of plants from the negative effects of sunlight and helps release nutrients into the soil. This will keep the soil cooler and prevent it from drying out.'