Does Watering Grass in the Sun Burn It?

You might have heard or read somewhere that watering your lawn on a hot summer day can scorch your lawn. I hate to break it to you, but this isn’t scientifically accurate.

Grass may indeed suffer some form of stress when you pour cold water on their hot leaves. But, this stress isn’t enough to classify as a burn, so don’t worry about burning your grass if you water in the sun.

However, if your lawn is still new, you might want to look into the best times to water during summer to avoid stressing your grass. Here’s everything you should know if you are wondering ‘does watering grass in the sun burn it ?’.

Does Watering Grass in the Sun Burn It

Does Watering Grass in the Sun Burn It?

There are a few dynamics to consider when watering grass during summer. First, let’s talk about what happens when you water grass when the sun is up. Does the water burn the grass? What really happens?

Many lawn owners have lived by the rule that you shouldn’t water your grass when the sun is up, but why is this the case? According to science, water droplets can bend and refract light and heat, thus acting as a magnifying glass.

Magnifying glasses can be used to burn objects if it is held at a certain distance from a light source.

This concept encourages the idea that the water droplets might act as a lens and concentrate heat onto the grass, thus burning the blades.

However, research done by scientists from Eötvös University in Budapest, Hungary, tried to figure out whether this phenomenon was true or just a myth.

The results found no evidence that watering grass on a hot day could burn the blades of the grass. Water droplets need to be at a certain distance away from the grass blade to focus light onto the leaf surface of the grass to burn it.

So unless you can suspend the water droplets in the air for long enough to focus light on the grass blades, you don’t have to worry about burning your grass.

They also found that the water droplets evaporated much faster than they could cause any visible damage to the grass blades.

 It is most likely that if you experience a grass burn on your lawn, it is due to another reason.

What Causes Grass to Appear Burnt?

Now that we know water doesn’t burn the grass during summer, let’s talk about what could be the possible causes of the ‘burnt’ look of your grass.

  • Excess salts. Your lawn could be dying due to excess salt build-up in the soil. If you have clay soil on your property, the salts may have compacted the soil, making it harder for grass to absorb nutrients.
  • Excess Fertilizer. Fertilizers containing nitrogen can easily cause a ‘nitrogen burn’ if applied in excess. These fertilizers also contain salts that continue to build up in the soil over time.

So how do you solve these problems? The easiest way is to flush your lawn with water to get rid of the excess salt.

If you notice areas of your lawn with pale yellow patches, it could be either of the above causes or due to dehydration. Flush the area with water for a few days and watch it regain its health.

If you notice spots that have turned brown completely, make sure to consult your lawn care expert for advice on what to do.

However, this doesn’t mean it’s okay to water grass when the sun is up. The cold water droplets landing on the hot leaf surface can cause psychological stress to the grass due to the temperature difference.

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Can I Water My Lawn on a Hot Day?

Of course. Your lawn grass needs more water on hot days than other days—however, it is crucial to get the timing right when watering your lawn on a hot day.

If your lawn is mostly shaded, then you don’t have to worry about watering during the day. However, if your lawn is directly exposed to the sun, the soil and the grass lose water much faster due to evaporation, so your lawn might get thirsty quickly.

Mature grass can go for a while without water since they have developed a robust network of roots that can pull water up from deep beneath the soil.

However, the grass can’t rely on its roots to supply it with water all the time. You need to understand the best time to water your lawn in summer.

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does watering grass in sun kill it

See also: Does softened water harm grass

What Is the Best Time to Water Grass in Summer?

Summer signifies the start of warm days and cool nights. This difference in temperature during the day and night plays a huge role in determining when to water your lawn. The heat during the day can cause your lawn to die due to drought stress.

The best time to water your lawn is in the early morning as the sun rises. The temperatures aren’t high enough to evaporate the water at this time. Water your lawn sufficiently to ensure it handles the summer heat well.

However, just watering once isn’t enough. You should also water again as the sun goes down before nightfall to cool off your grass.

Also read: Which grass can grow through mud

Is Watering Grass Midday Wrong?

Don’t water your grass when the sun is up if you can avoid it. However, this doesn’t mean you stand by and watch your lawn suffer as you wait for the sun to go down. Too much heat can damage your lawn and possibly kill it.

If you spot areas of your grass turning yellow or older grass wilting, it’s a sign your lawn is dying of thirst, and you should water it. Watering your lawn at midday may just save your lawn.

As discussed above, lawns get dehydrated quickly when the sun is overhead.

An easy way to tell if your lawn may be thirsty is to walk on it and look at the footprints left behind. If the footprint doesn’t spring back up, then your lawn is dehydrated, and you should water immediately.

Taking time to care for your lawn, especially on hot days, can help it flourish.


  • Ricky

    Hi, I’m Ricky. I’ve been involved in lawn care and landscaping from when I was 15. To be honest, I didn’t like the idea of pushing mowers, collecting grass clippings, and maintaining flowerbeds at the time. But having seem the passion my parents had for gardening and outdoors and the effort they put in maintaining the health and beauty of our landscape, I couldn’t help but not only admire their hard work but also I became a part of it. As someone who loves to spend time with nature’s best, I find myself learning a lot more about gardening and outdoors on a daily basis. Not to mention I love to share the knowledge I’ve gathered over the years with my readers at We Mow Dallas. To be clear, I don’t have a Master’s degree in gardening or anything like that. Everything I’ve learned about gardening, landscaping, and lawn care spring from passion and engagement with my parents. And with a ton of free information out there, plus the ability to run tests and determine what works best for lawn care and landscaping, every day is an opportunity to learn and implement something new. My goal with We Mow Dallas is to teach you exactly how to maintain your lawn and landscape. And since I walk the talk in reality, you shouldn’t hesitate to join me in this wonderful world of landscaping and lawn care. K Beatrice

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