Early in spring when your plants are smaller and the temperatures are lower you may only have to water every 3 or 4 days. As the plants get larger and the mercury creeps higher be prepared to water every day, with small pots or water “pigs” you might even have to water twice a day.
Usually when the first inch (2.5 cm.) or so of soil is dry, it's a good indication that watering is needed. In summer, watering outdoor potted plants is necessary daily (and even twice a day) for most species, especially when temperatures reach over 85 degrees F. (29 C.).
Over-watering can kill a plant more quickly than under-watering. Plants die when too much water in the soil causes the roots to suffocate and begin to rot. Often, the roots have already begun to succumb for rot before symptoms become obvious, and it's too late to treat.
Outdoor plants will need water every 3-7 days or when the soil is dry. A dry top doesn't signal a parched plant.
Trees, shrubs, perennials and most of the “permanent landscape” are fine when gardeners go away for a week or two of summer vacation. Potted plants and hanging baskets are more of a concern. These can wilt after just a day or two without water, especially in a hot, sunny spot and especially when recently planted.
Many houseplants can recover from missed watering. If your plant is very dry, it might lose some foliage, but most houseplants bounce back when watered.
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.
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.
Water the soil, not the leaves.
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.
Rather than watering on a set schedule, check first to see if your plants need water. If your plant is in a pot, check the surface of the soil in the pot either by looking at it or touching it with your finger. Wet soil will be dark in color while dry soil will be lighter in color.
Overwatering means yellowing leaves, a general feeling of flop (science calls it wilting!), fuzzy soil, and a pot that feels like it could double as a weight. Underwatering shows itself with crispy leaves, that same sad droop, and bone-dry soil.
Use a watering wand, drip irrigation or soaker hoses to direct water right to the root zone. Watering early or late in the day minimizes moisture loss due to evaporation from the soil surface. Shielding plants from wind will also reduce moisture loss.
To counter this, make sure to water the plants thoroughly, meaning soak them. Then, normal watering routine should be you water half the amount, go to another plant, and come back. It moistens the soil on top, and allows more to sink in. You need that water to get all the way down the pot.
Run your sink into a watering can, cup, or bucket, and let it sit for a good 24 hours. This will allow chemicals like chlorine and fluoride the time to evaporate from the water. We like to have a full watering can ready to go with still water so that if our soil seems dry, we can water our plant without waiting a day.
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.
“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.
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.
Most plants want to dry out at least a bit between waterings. It doesn't rain every day; so they don't need water every day. Ensure soil is fully saturated when watering (drainage is a good indicator). Your plant doesn't want a sip, it wants a full drink.
This depends on the plant types, garden light conditions, and weather. Plants in shaded areas may last longer without water compared to those in full sun. Container and window box plants can dry out in a day, whereas many houseplants can manage with one watering per week or less.
Outdoor plants are a great addition to any home or patio area. Figuring out the perfect balance of water to help keep them healthy and looking great is a must. Misting your outdoor plants is a great way to ensure you get enough moisture without overwatering them and without underwatering them.
Deep watering entails watering at a slow pace for long enough that the water soaks deep into the soil, where the roots are. Often this means watering for 30-60 minutes at a time, 2-3 times each week, until plants are established.
Most plants need about 1 inch of water per week. So if you haven't received an inch of rain, then you'll need to give your plants a drink. Even if you have received rain, it's still a good idea to check the moisture level in your soil to see if your garden needs additional water.
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.
While you will need to tailor your watering schedule to the above factors, most established gardens need about 1 inch of water weekly. "This water quantity can come from a combination of rainfall and your watering efforts," says Mathis. "As you grow your plants, you'll find the timing that works best."