Houseplants, container plants, vegetable gardens, lawns, and ornamentals have specific watering needs. In many cases, too much water can be just as damaging as not enough. Knowing how much and how often to water will help you raise healthy, attractive, and productive plants in the most effective and efficient way.
Check plant tags or look online to learn each plant's water requirements, and follow these tips to learn how to water your plants in a variety of conditions.
1. Water Thirsty Plants Immediately
When a plant, even if it is well-established, looks wilted and under drought stress, water it right away. Always check the soil first, though: often plants look stressed and droopy because they've been overwatered.
2. Water When the Soil Is Dry
For all other plants, water when the soil is dry. To check, stick your index finger in the soil about two inches deep. Note that not every plant needs to be watered and will die when the soil is dry; there are many drought-tolerant plants. If you don't know your plants' water needs, check the plant tag or look up the plant online.
Some plants, like succulents, prefer for the soil to dry out between waterings, while other plants need consistently moist soil.
3. Don’t Water Cool-Season Grasses
If your lawn consists of cool-season grasses such as Kentucky bluegrass, perennial ryegrass, fine fescue, and tall fescue, these go into dormancy in hot and dry summer weather—a protective mechanism that allows the grasses to survive dry spells.
A newly planted lawn, however, is different, it needs regular watering when the soil is dry to get established. Do not let newly seeded grasses dry out--keep seeds moist.
4. Give Vegetable Gardens Get One Inch of Water Weekly
In the absence of sufficient rain, you need to water your vegetable gardens or raised beds with at least one inch of water every week. In hot climates, you may need to water more often. Check the soil--stick your finger into the soil one inch deep. If it's moist, no need to water.
5. Adjust Watering to the Type of Plant and Garden Soil
The required amount of water depends on the type of plant, its size, age, and your local climate. The type of soil is also a determining factor in the amount you need to water. Sandy soil drains much more quickly than clay soil, so it will need more frequent watering. Mature plants may be more drought tolerant than young plants.
6. Water Plants at the Base
Let the water go right to the center of the root system by targeting the base of the plant with the nozzle of a hose or watering can. Overhead watering with a hose is not only a waste of water, but wet leaves can also precipitate the spread of fungal diseases.
Trees, with their extensive root systems, need watering in a wider area, beneath the entire canopy and extending several feet beyond the drip line, but start with center, or root ball. Getting the ball soaked is always the first step.
7. Water Early in the Morning or Evening
The early morning hours are the best time to water, but the late afternoon or early evening are also good times to water.
8. Water Deeply
Watering deeply and infrequently is much better than shallowly and often, because the water needs to reach the roots. Also, watering deeply will train and encourage the plant to seek out water deeper and farther from the root ball.
9. Slowly Soak Dry Soil
When the soil is dry, it is important to slowly soak the first top inches at a very low watering volume, otherwise the water will just run off. Once the water seeps into the soil, you can increase the watering volume.
10. Always Water New Plants
During the first year after planting, all newly planted trees, shrubs, and perennials need more frequent, regular watering than established plants and need to be watered in the absence of rain. Some trees may even need a couple of years or more to get established.
11. Water Seeds and Seedlings at Least Daily
Vegetable, flower, and grass seeds, as well as young seedlings also need watering at regular intervals. Water daily, as often as twice a day in the absence of rain, and even more in hot, dry weather.
Seeds easily dry out during germination and young seedlings are much less resistant to heat and dryness than established plants. Always check the soil first to see if water is needed. Too much water can also harm seeds and seedlings.
12. Water Seeds and Seedlings Gently but Broadly
Water seeds and seedlings gently with a fine spray nozzle so you don’t wash out the seeds or knock over tender seedlings. Water them broadly to get the entire soil area wet (the rule of targeted watering does not apply to seeds and seedlings).
13. Water Outdoor Container Plants at Least Daily
Container plants need much more and frequent watering than plants in the ground. On hot days, water them daily, or even twice a day. Check the soil first.
How fast the soil of container plants dries out depends on the type of container. Metal, terracotta, and coir (the material used for hanging baskets) dry out especially fast, so keep an eye on those. Also, sun exposure of the container greatly increases the rate of evaporation.
When planting in containers, remember to always choose a container with a drainage hole and saucer to avoid root rot.
14. Water Outdoor Plants With Tap or Rain Water
For outdoor plants, well water, rain water, and tap water are absolutely fine. The chlorine in tap water does not affect outdoor plants because the amount is so small that it does not impact the growth of microorganisms in the soil.
15. Don’t Let Houseplants Sit in Water
Empty the trays of houseplants to avoid having them sitting in water, which can cause root rot.
16. Water Houseplants with Tepid Water
For houseplants, the water should ideally be at room temperature. Ice-cold water can damage their roots.
17. Remove Chlorine When Watering Houseplants
While tap water is also fine for most houseplants, some are sensitive to chlorine and fluoride. You can easily remove chlorine from tap water by letting it sit in an open vessel for a day to let it evaporate. Fluoride cannot be removed from the water, therefore sensitive plants should be watered with rain water, distilled water, or the water from a dehumidifier.
18. Do Not Water Houseplants With Softened Water
If you have a water softener in your home, tap water is not suitable for houseplants due to its salt content. Use water from an outdoor spigot or water the plants with rainwater.
19. Mulch to Cut Down on Watering
The best thing to cut down on watering is mulching, which not only retains moisture in the soil but also keeps the soil cool and suppresses weeds.
20. Choose Plants With Low Watering Needs
Plants introduced from other continents often have high watering requirements. Consider native and xeriscape plants, which are much better adapted to your local climate.
“Impact of Watering Lawns and Gardens with Chlorinated Water - PlantTalk Colorado.” Colorado State University website
"How to water indoor plants," Missouri Botanical Garden website