Avoid watering grass on a hot afternoon when it's 95 degrees or higher. The best time to water grass is at dawn or in the early evening. Water deeply three times a week instead of a little water daily. Test whether your sprinkler system is watering your lawn evenly.
Watering on a hot summer afternoon is a horrible idea. The liquid will evaporate too quickly and may not reach your grass's roots, so heat and irrigation shouldn't go together. Instead, the best time to water grass during summer is in the morning.
Most lawn experts recommend watering your grass until the soil or ground temperature reaches the 40-degree Fahrenheit mark.
It's tempting to water your lawn in hot weather, especially if your grass is already looking a bit thirsty. But in most cases, you shouldn't water your grass when it's 95°F or hotter because the water will likely evaporate before it reaches the roots.
In times of extreme heat, it is vital to water your lawn for about 30 to 45 minutes daily. Once the temperatures drop below ninety, you can cut back to watering three to four times a week, until that blissful thunderstorm comes and quenches your lawn's thirst!
Highlights. Avoid watering grass on a hot afternoon when it's 95 degrees or higher. The best time to water grass is at dawn or in the early evening. Water deeply three times a week instead of a little water daily.
If it's 70-80 degrees outside try watering 2-3 times a week. During the spring your lawn will be fairly easy to manage so you don't have to water all the time. In the blazing summer, when temperatures are between 90-100+, try watering 3-4 times a week.
During extremely hot weather (daytime temperatures above 90F and nighttime temperatures above 70F), try to water daily or every other day. In a 10x10-foot garden, this would mean giving your plants 8 to 9 gallons of water each day.
Most oscillating sprinklers will put off about one inch of water an hour. That would mean that you would need to water your lawn for one hour, once a week (twice weekly in periods of extreme drought). For less established lawns, you may need to increase the frequency as your lawn's root system becomes more robust.
While seasonal heat is cyclical, an unexpected heat wave poses a different threat, and you'll need to take more action than normal. Your lawn will likely require additional watering during a heat wave, but always water strategically.
Grass generally stops growing once temperatures drop to below the range of 50-55 degrees Fahrenheit or reach above 90 degrees Fahrenheit. Since soil takes longer than air to lose and retain heat, it will take a period of a least a few days for a temperature change to impact the growth of grass.
If the daytime temperature is below 60°F then soil temperature is below 50°F, making it too cold; if there is frost or still a danger of frost, then it's too cold. If it's too cold, the grass seeds will likely rot.
Grass needs the benefit of the day to dry and heal before dusk settles. Since mowing your grass in the early morning can damage it and mowing it during the early afternoon can burn it because of all the high temperatures, the ideal time is mid-morning. That is of course if you're free during that time of day.
If the plants pull out from the ground easily, they're probably dead. If the roots hold fast when pulled, the plants are dormant. You will also see the difference when you start to water or when rain returns as moisture will revive brown grass. However, it will not bring dead grass plants back to life.
Established Lawns
In general, you want the top 6-8 inches of soil to be moist, but not soggy—which translates to 1 to 1.5 inches per week. Watering deeply, but infrequently, leads to stronger root development and drought-resistance than watering briefly every day.
If your sprinkler output is 1½ inches per week, your sprinklers should run for only ⅓ hour or 20 minutes that week (½ divided by 1½). On a twice-weekly watering schedule, run your sprinklers 10 minutes each time.
Sprinklers generally cover up wider ground and spread out water at a slow yet steady pace, which makes all the soil moisturized evenly and soaked underground. A watering hose takes time to cover space and can clutter the soil if there's too much water.
The average system uses approximately 15-16 gallons per minute, per station.
Hands down, the best time of day to water is early in the morning. Watering during the day can increase risk of disease. If you can't water early in the morning, water late in the evening, especially before days forecasted to have dangerously high temps.
During really hot weather, water your vegetables at least two to three times a week. Watering the garden deeply is critical. The water must go down, down, down to encourage deep roots and get away from the hot soil surface.
Vegetables and fruits that are developing fruit during a heat spell need regular watering to ensure good production. Vegetables typically require daily watering during summer weather, but may need a second watering when temperatures are extremely high.
The heat of summer can be a death sentence for your plants, but over watering can as well. The best thing you can do is keep the soil moist by watering when the top 1 inch (tip of your finger) feels dry to the touch and to be aware of the symptoms listed above.
National Geographic's article titled, "How 100 Degrees Does a Number on You" states, "A normal, healthy person who is not used to the heat can, in heat wave conditions, sweat as much as 1.5 quarts of liquid in an hour.