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.
Wetting leaves.
Plants get their moisture through their roots, not their leaves. Direct watering to the soil surface and avoid wetting leaves because water helps spread some plant diseases. Use a watering wand to reach ground level or a soaker hose or trickle irrigation system to wet the soil rather than the leaves.
1. Watering Plants At Night Isn't Needed: Although the idea has been around for years, most plants don't need extra care by watering them at night. There are a few exceptions, but 99% of your plants, indoors and out should only be watered during the 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.
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.
Thank you for your question. The ideal water temperature for watering plants is between 62-72°F. Within this range, the water is not too cold and can still hold a good amount of dissolved oxygen.
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.
The best time to water plants is in the morning or evening.
More importantly, watering at these times actually helps the plant retain water. If you water in the afternoon, especially during summer, the heat and sun are at their peak and the plant's water will evaporate instead of absorbing into the soil and roots.
The notion that wet leaves on sunny days cause scorch in plants was disproved nearly ten years ago. But there is no doubt that watering in full sun is not water efficient – as much of it will evaporate before entering the soil. In the current hot breezy weather it is probably best to water in the early evening.
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.
Even in wet seasons, watering usually helps, because the water that falls then isn't all available to plants. Roots need air to function, and a “cats and dogs” rain temporarily drives all the air out of the ground.
Q. How much water do plants need a day? Plants don't need daily watering. Instead, water deeply but less frequently.
Poor drainage or improper watering
Water issues — either too much or too little — are the leading reason behind yellow leaves.
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.
Misting is highly recommended at least once a month, and more often with species that enjoy it (see full list below). Be sure to spray the top and underside of your leaves, and if using for cleaning your leaves, wipe the leaves down with a cloth after misting to remove dust.
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.
Watering at night is not the best for your plants' leaves or overall health. Here's why. 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.
Keep in mind that morning sun, which is cooler and less intense, is easier on shade loving plants then the hot afternoon sun. Plants that receive too much intense light will scorch if pushed into too much hot sun.
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 Plants and Lawns Efficiently
DO water early in the morning when sunlight is weakest, the ground is coolest and foliage will have hours to dry before nightfall. Aim for between 5 a.m. and 10 a.m. DON'T water in the evening when soil is warm and wet foliage can attract insects, fungus and disease.
We recommend watering your plants twice daily -- early morning and late afternoon. To be more specific, early morning means 7-10am; and late afternoon means 3-5pm.
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.
As the weather heats up and plants reach full size, you may need to water containers (and especially hanging baskets) twice a day.