Check the leaves for wilting and test the top inch of soil with your finger to see if it's dry enough to need a drink. Test Garden Tip: You're more likely to overwater indoor plants than underwater. Too much water will drown your plants. A good rule of thumb is to let the top inch of the soil dry out between waterings.
How often should plants be watered? Water once or twice per week, using enough water to moisten the soil to a depth of about 6 inches each time. It's okay if the soil's surface dries out between waterings, but the soil beneath should remain moist.
The best time to water plants is in the morning or evening.
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 the weather heats up and plants reach full size, you may need to water containers (and especially hanging baskets) twice a 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.
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.
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.
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.
The second-best time is late in the afternoon or early in the evening. Try not to water at night. Night-time watering is not ideal because your plants' leaves may not be able to dry off as quickly as other times of day. Wet leaves are more susceptible to diseases.
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.
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.
When you water be sure to moisten the entire root zone. In other words, water until water comes out of the drainage hole in the bottom of the pot. It may take as much as ¾ or a gallon of water to thoroughly water a 10 to 12 inch container.
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, however, you apply a pint of water every day, and the soil stays constantly wet, that is over watering. This can lead to unhealthy roots or even root rot. Soil that stays constantly wet from frequent watering deprives the roots of the oxygen they need.
Stunted slow growth accompanied by yellowing leaves is also a symptom. Leaves falling off often accompanies this symptom. If your plants have yellowing leaves and old leaves, as well as new leaves that are falling at the same accelerated rate, you are overwatering.
By regularly spraying your houseplants with water, you raise the humidity around their leaves, keeping delicate species from the tropical regions of the world happy in distinctly untropical homes.
For almost all plants, you should water them only when the top inch or so of soil feels dry. An easy way to check if your plant needs watering is to follow the finger dip test. Never be tempted to over-water. Over-watering is equally as harmful as under-watering.
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.
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.
So, how hot IS too hot for plants? The general answer is around 90 degrees F, with some exceptions to the rule.
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.
Reduce Evaporation
Mulch after watering with organic material such as compost, leaves or grass clippings to shade the soil and keep the root zone cooler. Shade the soil with a living mulch by planting densely and/or using plants like squashes that are vigorous or have large leaves.
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.
WATERING SCHEDULE
Deep watering helps to encourage deep root growth. Deeper roots stay cooler and stronger to better protect your lawn and garden from heat stress. Allow a deep watering at least once per week, twice if the temperature exceeds 100 degrees or more for several days in a row.