Most plants shut down during extreme heat, so if it is over 100 degrees, it may be best to wait to water even if your plant is stressed. Throw a damp sheet over it, or mist it lightly to bring the temperature down.
When. 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.
Avoid watering when temperatures are below 40°F or when sustained freezing temperatures are expected within 24 hours as this water will freeze and not be available to the plants.
In hot weather you need to water in the mornings when it is cooler. This will allow more water to reach the root system before it evaporates in the heat. There may be times when you cannot schedule watering in the morning. In this case, water the plants in the late evening before bed.
So, how hot IS too hot for plants? The general answer is around 90 degrees F, with some exceptions to the rule.
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.
Often this means watering for 30-60 minutes at a time, 2-3 times each week, until plants are established. When temperatures normalize, continue with deep watering, but back off to 1-2 times each week. Tree bags are fine to be used for newly planted trees, but only for short periods of time.
Most plants shut down during extreme heat, so if it is over 100 degrees, it may be best to wait to water even if your plant is stressed. Throw a damp sheet over it, or mist it lightly to bring the temperature down. Mist leaves with a spray nozzle to cool down plant and reduce transpiration.
If you forget or are too busy to water your plants on some summer mornings, you can water them at night. However, this should not be your ordinary watering time. Morning is the proper time for watering plants, though you should keep in mind that not all plants need daily watering.
As the weather heats up and plants reach full size, you may need to water containers (and especially hanging baskets) twice a day.
Morning watering is actually preferable to evening watering as the plant has time to dry before the sun goes down. At night, water tends to rest in the soil, around the roots, and on the foliage, which encourages rot, fungal growth, and insects.
As long as you don't overheat the roots of your plant and you protect the leaves and crown from the heat, watering with hot water will have no harmful effects. In fact, it's better to water with hot water than it is to water with very cold water.
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.
Overly dry soil is a sure sign that plants will develop heat stress. Water is essential for plants to live. During a heat wave, correct watering is even more important. Early-morning or early-evening watering is the best time to provide moisture to all your plants in the garden or landscape.
If the soil feels dry, it's time to water. In the spring and fall and in cooler climates, it might be sufficient to water container plants every two to three days. In the summer and in warm climates, container plants usually require daily watering, unless they are succulents or other drought-tolerant xeriscape plants.
The best time to water outdoor plants is in the morning when temperatures are usually cooler. This gives the plants time to absorb the water so they can get through a long, hot day. The second-best time is late in the afternoon or early in the evening. Try not to water at night.
After a night time soak, leaves can stay wet for a pretty long time since they don't have the day's sun to dry them off. Because of this, damp leaves become extra vulnerable to fungal development. Try to avoid watering late, especially if you live in a climate with humid nights.
It can rain at any time of the day. But inside, where you're in control, there actually is an ideal time to water: the morning! Most plants like to be watered in the morning hours. They need to bulk up on water before the sun is shining in full force and cooks the water off.
There is a high likelihood that plants are experiencing heat stress if they wilt during the day's hottest period and then revive in the evening or morning. Dried Leaf Margins. Some types of crops dry off the leaf's outer edges to ensure survival.
Signs Your Plants Are Too Hot
The leaves dry out. Excessively hot plants will dry out faster. The leaves turn yellow. One of the causes of yellow leaves is excessive heat, so this is one thing to consider!
During spring and summer in Southern California, she suggests drip watering three times a week for 18 minutes, then adjusting from there if the soil is too wet or dry. Don't know how to tell? Stick your finger in the soil. If it's consistently moist 2 inches down, your plants are fine.
If your plants are in the ground (versus a pot), the general rule is that plants need one inch of water per week. However, this does NOT mean watering one time per week. That doesn't usually do the job. Plants do best when watered deeply about three times a week, factoring in the rain.
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.