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Does Watering Grass in the Sun Burn It? Myth Unveiled!

Are you suspicious that the patches of dried lawn grasses result from watering in the sun? The short answer is no!

Watering grass in the sun does not burn it, no matter the time of the day and sun intensity. But avoiding burnt lawn grasses requires watering at a suitable duration and capacity!

In fact, you should know about the correct watering schedule, especially in hot weather, to avoid burnt grasses.

Read on to unravel the mystery that is watering the grass correctly.

When to Water Grass in Hot Weather?

Many seasoned gardeners advise not to water the lawn during the heat wave or in the high sun.

A temperature above 77°F may stunt root growth, and anything above 90°F will damage the shoot growth.

As a result, the long dry period can lead to drought with dry and browned grasses.

How Often to Water Grasses in Summer?

Almost all lawns require 1-inch of watering every week, which will significantly increase in hot weather.

The grass should receive between 1 and 1.5 inches (25-38 mm) of water each week during the summer between irrigation and natural rainfall.

Generally, you should water your lawn 2-3 times per week in summer, especially if there is no rainfall.

There are a few ways to ensure that the lawn gets ample water.

  • Use a rain gauge to measure water when you turn on the sprinklers.
  • Alternatively, place a can in the lawn and measure up to 1 inch.
  • Otherwise, use a moisture meter to test your lawn’s moisture between watering.

Similarly, most cool-season grasses demand high water consumption than warm-season grasses.

Open Lawn
Lawn is best watered early morning in the noon when the sun is low

Tending for cool-season grasses in summer means frequent weekly watering, about three times, including Tall fescue, Annual bluegrass, and Annual ryegrass.

Here is a chart describing the water intake for different grass types.

Grass TypeWater RequirementEvapotranspiration
American buffalograssVery low<6 mm p. day
Hybrid bermudagrass, Centipedegrass, Dactylon bermudagrass, ZoysiagrassLow6-7 mm p. day
Hard fescue, Chewing fescue, Creeping red fescue, Bahiagrass, Seashore paspalum, St. AugustinegrassModerate7-8.5 mm p. day
Perennial ryegrass, KikuyugrassHigh8.5-10 mm p. day
Tall fescue, Creeping bentgrass, Annual bluegrass, Kentucky bluegrass, Rough bluegrass, Annual ryegrassVery high>10 mm p. day

Is it OK to Water the Grass During the Day?

Avoid watering the grass when the sun is directly above your head!

The water will quickly dissipate from the grass and fail to reach the roots as the liquid evaporates too quickly.

Besides, you should water the lawn early morning or before 10 am to let the liquid settle around the roots. 

It is also ideal to wait for the temperature to fall which be around 3 or 4 p.m. in the late afternoon. 

When to Avoid Watering the Grass?

You can water your grasses on a cloudy day as long as your lawn needs one.

However, strictly avoid misting grasses in the evening (10 a.m.-2 p.m.) or night as the cooler condition will ideally invite fungal growth and attract pests.

Slugs and other pests lurk at night, looking for moist and humid locations, such as a wet lawn.

Remember, transpiration is essential for the grass to maintain its water intake/output, which is impossible when watered at night.

Watering grasses at night helps save water, but it is only a myth! In fact, the opposite is true -always water in the morning and sometimes afternoon, but never too late.

Find out how often to water your lawn to grow grass seeds.

Will Grass Burn if Watered in the Sun?

Nope, your lawn grass will not burn when even watered in the hot summer.

Many novice gardeners fear the water droplets will magnify sunlight on the grass, leading to burns, but it is only a myth.

The water droplets are minuscule to focus the sunlight sufficiently to damage the grass.

But it is a bad idea to water midday because the scorching sun will quickly evaporate the water from the ground, leaving the lawn dry.

So, do not shy away from watering the lawn if it has experienced an extended drought!

What Causes Grass Burns?

Here are some probable reasons your lawn grass is burning or turning yellow.

1. Salt build-up

Using mineral or chlorinated water on grass will leave salt residue on the ground.

The accumulating salts will choke the grass root, prevent the water intake, and leave the grasses dry, inviting yellowing.

Similarly, under-irrigating the lawn will also allow the salt to accumulate in the soil, leading to the yellowing of grasses.

2. Over-fertilizing Condition 

You are more likely to burn your lawn with fertilizer than with too much water.

Over-fertilizing the lawn, using synthetic plant food, and feeding in high summer will stunt grass growth.

Remember, excess fertilizer will cause the nitrogen and salt levels to spike, leaving the grasses yellow and wilted.

3. Ground Pollutants

Synthetic fertilizer residue, chlorine, fluoride, leaf litter, and weeds harm lawn health.

These pollutants often litter the lawn, affecting soil aeration and optimal water intake by the grass.

The grass will fail to thrive with poor soil quality, leading to premature yellowing.

4. Overwatering Condition 

Under-irrigation affects the grass’s health, and overwatering the lawn will prevent the thatch (undigested roots, leaves, and other organic matter) from breaking down.

Thatch, ¾ inches or thicker, prevents the oxygen supply to the grassroots and creates an ideal habitat for fungus growth.

The fungus growth leads to root rot and yellowing of the grass leaves.

If you need to identify grass flowers, first learn about spikes, racemes, and panicles!

How to Water Grass in Hot Weather?

A flourishing lawn with lush, green grass is the dream of every gardener, best achieved by watering appropriately and providing optimal care.

Here are some proven tips for caring for your lawn grass in hot summer.

1. Water Accordingly

Remember, the water requirement will differ from season to season, i.e., more water in the hot summer.

The grass needs 1-1.5 inches of water every week, which is met by weekly irrigation and rainfall.

However, if rainfall is spare, you should increase weekly irrigation to bi-weekly or tri-weekly.

When watering 2-3 times a week, consider spraying the water for 15 minutes. Otherwise, give your lawn a full 20-30 minute spray each week.

2. Aerate the Lawn

Poor drainage and compact soil condition are bad news for the lawn grass.

You would know this by yellowing grass, puddles, and thinning or bald patches.

So, consider aerating your lawn with an electric or manual aerator once every week, which is best done before summer.

Aerating the soil will break down clumps to increase air circulation inside the ground.

3. Get an Automatic Sprinkler System

Investing in a smart sprinkler system will save you bills and water in the long run.

Installing an underground sprinkler system reduces water usage by optimizing the watering according to the time and day of the year.

grass watering
Invest an in automatic sprinkler system to automate grass watering based on weather, time of the day, and temperature. 

The smart sprinkler system comes with a moisture sensor and mini-weather station to optimize watering, frequently during high summer and less during cooler months.

4. Let Your Lawn Go Dormant

Let your lawn be dormant in the hot summer if you have cool-season grasses.

This grass-type flourishes in fall and winter but turns brownish in summer.

So, overwatering the lawn or applying fertilizer in summer will only harm the roots.

Instead, reduce watering to once every 2-3 weeks and apply fertilizer in late summer to boost the young grass growth.

From Editorial Team


If you live in a water-restricted area, consider harvesting the rainwater in a rain barrel, dramatically reducing your consumption.

Remember, a healthy lawn always looks greener and packed in the growing season, where bald or yellowed patches may indicate something seriously wrong!