You should avoid watering the actual leaves or foliage of your plants because water droplets that stay on the leaves can scorch them if left in the blazing sun. Besides, just spraying water on top of your plants is not enough. You have to soak your plants directly at the root system.
The standard rule of thumb is to give your flowers and vegetables the equivalent of 1 inch of water per week (and as much as double that amount in the peak of summer). “Stop (watering) when the soil is moist but not waterlogged,” Pappas adds.
LPT - overwatering kills more plants than underwatering Source: BSc. horticultural science and former garden centre owner. More often than not, well intentioned gardeners (indoors and outdoors) kill their plants with too much H2O. The best thing you can do for (most of) your plants is let them dry out between watering.
Plants get their water from the roots, not the leaves so it is better not to put water on the leaves. If you leave water on the leaves it just evaporates or drops into the soil.
Provide Slow, Deep Watering
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.
“Spritzing your plants is not the correct way to water your plants. In fact, it doesn't water them at all,” she says. While spritzing can provide some moisture, unless the plant really thrives in humidity (ferns, orchids, or bromeliads, for example), Hovis says spritzing can do more harm than good.
The good news is that most plants will bounce back between 7-14 days if they're given proper care (which includes rehydration). If this isn't possible because major damage was done or little healthy root system exists then expect about 2 weeks until improvement can be seen.
Feel the Soil: The simplest way to gauge your plant's watering needs is by feeling the soil. Turns out that old trick of sticking your finger into the soil up to the knuckle has merit! If it's soggy or has standing water, you're overwatering. If it's dry an inch below the surface, it's time to water.
Our hypothesis was confirmed; the more water the fast plants received the more the plants grew. The correlation between the water intake and plant stem height is apparent when Figure 2 is observed; the plants that received 50 mL of water had much greater growth compared to the plants that just received 5 mL of water.
Even though we commonly say, "water the plants," it's important to water the base of a plant (i.e., the soil) instead of the plant itself. Water should be poured onto the soil, not the leaves or flowers. This ensures that water ends up where it's needed—at the roots.
If you have a wilting plant the first thing you want to do is give it a thorough watering. You can accomplish this by putting your plant in the sink, or adding watering for anywhere from 3 to 8 minutes (depending on pot size and specific plant/soil requirements), letting the water completely drain out of the bottom.
The best way to tell if your plants need water is to stick your finger about an inch into the potting mix—if it feels dry, break out the watering can. If you detect dampness, check back again in a day or two. For smaller houseplants, you can also pick up the whole container. If it feels light for its size, add water.
Don't Water at Mid-Day in the Sun. "Don't Water Your Plants in the Middle of the Day!" How many times have you heard that? "Only water your plants in the early mornings or late evenings." THE CHALLENGE: That's easy to say, but not always easy to do.
As long as you are allowing the plant to dry out between waterings you won't overwater your plant. Also don't leave your plant in the water for too long. Keep an eye on it. Once you do this long enough you will figure out how long each plant needs to be fully watered.
Some plants, especially edible crops, come with specific irrigation instructions such as "provide one inch of water per week." One inch of water is 0.68 gallons per square foot.
Usually underwatering a plant is less damaging than overwatering, which can cause additional problems like root rot and other diseases. But of course, if a plant is too dry it can shrivel up before you even realize it.
Leaves Turning Bright Yellow or Mushy Stems
This is usually a sign of overwatering, either caused by watering your plant before it's ready or if your plant is in too low of light. When plants sit in waterlogged soil, their roots can't get enough oxygen, leading to root damage which manifests as yellow leaves.
When a plant is first becoming overwatered, leaves turn yellow. If soil doesn't have a chance to dry out before you water again, leaves start to wilt. When overwatering is the problem, wilted leaves are soft and limp. (If too little water is the issue, wilted leaves are dry and crispy.)
How to check for root rot. The main signs to look out for are: yellowing, wilting leaves, wet soil that isn't drying, black, wet roots, quickly declining health, and stunted growth.
In addition to watering your houseplants regularly, some species also benefit from the occasional misting. Misting houseplants can improve humidity, which is beneficial to tropical varieties that thrive in humid environments.
If you water thoughtfully, you'll put water where your plants really need it and avoid wasting it. Water the soil, not the leaves. Trees and plants can only absorb water through their roots. If you're watering by hand with a hose nozzle or watering wand, direct the water toward the base of the plant.
Water the roots: Instead of drenching the leaves, water should be applied to the soil around the plant's base. It's crucial to focus on the roots, which are responsible for absorbing nutrients and moisture. Avoid watering the foliage, as this can lead to disease and damage.