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.
Is it OK to water plants at night in summer? It is OK to water plants at night in summer – although the morning is better. 'It's not the end of the world to water in the evening as it's one of the cooler times of the day and can allow the roots and soil to soak up the water for good hydration,' says Tom Hilton.
Evening watering gives plenty of time for the water to penetrate the soil and for the plant to take it up, but there is a concern that leaves staying damp overnight will provide access to disease.
Watering indoor and outdoor potted plants at night can increase the chances of root rot. Even a little water left in mulch or soil consistently can damage the root systems, which can cause the plant to struggle to grow.
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.
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.
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.
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.
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.
Late afternoon through around 6 pm, or even later in the summer when days are long, is okay. Is it OK to skip a day of watering? It depends on how dry your plants are. If they are very dry, then water them; but if they are still wet, you can skip that day.
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 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.
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.
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.
Because there is no sun to evaporate the puddle, your plants' roots become suffocated from reduced air and moisture. Your plants' stem and crown may also be harmed from pathogens or rot if the water concentrates around each plant base.
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.
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.
Water the Soil, Not the Foliage
Plants absorb water through their root systems, not through their leaves, stems, or flowers. Thus, to properly water your containers, apply water to the soil where it will reach and be absorbed by the plant roots.
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.
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.
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.
Don't fertilize plants or trees during hot summer months
During hot spells, it is especially hard to keep up with plant water and nutrient needs as soils dry out quickly and water may not be readily available. Save your plants (and yourself!) from stress by stopping fertilizer application before hot weather hits.
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.
Light freeze - 29° to 32° Fahrenheit will kill tender plants. Moderate freeze - 25° to 28° Fahrenheit is widely destructive to most vegetation. Severe or hard freeze - 25° Fahrenheit and colder causes heavy damage to most plants.