The best time to water your garden in summer is from 6 am to 10 am—before the heat of the day sets in, giving your plants plenty of time to drink up and any moisture on the leaves to dry off before nightfall. What is this? If watering in the morning isn't possible, the next best time is from 4 pm to 7 pm.
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.
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.
Watering in the heat of the day shouldn't hurt the plants -- it actually cools them off -- but it's a far less efficient use of water as much of it will evaporate before reaching the roots. Avoid getting plants wet late in the day unless it's the only possible time you can water them.
Established Plantings
Use a soaker hose or sprinkler for 30-60 minutes at a time. During normal summer temperatures, this type of watering can happen every 2-3 weeks. In times of extreme heat, 1-2 times each week may be necessary. Know your plants though!
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.
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.
Avoid full sun
In the current hot breezy weather it is probably best to water in the early evening. This gives the plants enough time to dry out, but there is still the chance for overnight water uptake by the roots. And if you want to water in the morning then start very early – before the sun is shining.
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.
As the weather heats up and plants reach full size, you may need to water containers (and especially hanging baskets) twice a day.
Higher temperatures cause the plant cells which control the openings (stoma) where water is released to the atmosphere to open, whereas colder temperatures cause the openings to close. Wind & air movement: Increased movement of the air around a plant will result in a higher transpiration rate.
If you are unsure how long to water new plants, aim for 30-60 seconds for small plants – longer for larger plants while moving the hose to a few locations around the plant. Avoid watering when the soil feels moist. The earth must be allowed to dry out between watering.
There's no cut-and-dry definition of a deep watering. Most gardeners generally refer to it as when water has soaked at least eight inches into the soil. This gives plants the structure required to survive lack of water, whether from a drought, a busy gardener, or other environmental stresses.
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.
We should water the roots so that the plant grows healthy.
Leaf scorch is caused by failure of the tree to supply enough water to the leaves at a critical time, usually in July and August. A great amount of water evaporates from the leaf surface because of sun and wind during hot, dry weather. If the water supply is deficient, the exposed leaves dry out and scorch.
Most plants slow down their growth and production in temperatures above 90 degrees.
Best Water for Houseplants
Most tap water should be fine for houseplants unless it is softened because softened water contains salts that can build up in the soil over time and cause problems. Chlorinated water is also safe for most houseplants, but if you have a filtration system, that's much better for your plants.
Most of the houseplants we grow originated in the tropics or sub-tropics where rainfall is relatively warm. Ice cold water will cause root shock, which may lead to permanent root damage, leaf drop and other problems. Allow the water to warm to room temperature before watering the plants.
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.
Mulch, mulch, and mulch some more!
Cover your soil with a blanket of organic material such as straw, leaves, shredded paper or cardboard, or bark. This will moderate soil temperature, prevent runoff and evaporation, and hold moisture in the for longer periods between waterings.
Q. How much water do plants need a day? Plants don't need daily watering. Instead, water deeply but less frequently.
It is so hot out there!
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.
The optimum temperature for roots to absorb water and nutrients is around 68°F. At that temperature, the water in the substrate still contains a lot of oxygen, and it is also exactly the right temperature to trigger the pump mechanism in the roots.