The Dos and Don'ts of Watering Plants

The Dos and Don’ts of Watering Plants
How, when, and where you water your garden and houseplants can critically impact their greenery and blooms. Read on for the best ways to ensure success.
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Whether you’re a green thumb or not, you probably already know that all plants need water to thrive—after all, that basic knowledge goes back to introductory middle-school science class. What you might not know is that incorrect watering techniques can put plants at risk for disease and even kill them. Whether you want to cultivate pretty outdoor perennials or you just want to properly care for your new houseplant, heed these best and worst practices for watering plants and you’ll reap healthy, happy specimens.
Watering Outdoor Plants
DO hydrate plants in the morning.
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The most efficient time to water outdoor flowers and vegetables is early in the day, when the soil is cool and water has the best chance of seeping down to the roots of the plants before it evaporates. Watering plants in the morning will ensure that they have sufficient store of moisture beneath the soil to withstand the heat of a hot summer day.
DON’T water too frequently—or not frequently enough.
Especially during hot weather, it may be tempting to water just enough—and often enough—to keep the soil damp. Shallow surface watering, however, discourages deep root development. Instead, opt for a less frequent watering routine that thoroughly saturates the soil. This method encourages the plants’ roots to reach deeply for residual water, even when the surface of the soil appears dry. The standard rule of thumb is to give your flowers and vegetables the equivalent of at 1 inch of water per week (and as much as double that amount in the peak of summer).
DO water plants at soil level.
Directing water at the base of your plants delivers the hydration right where it’s needed: the roots. Consider winding a soaker hose between plants in a flower or vegetable bed to soak the soil slowly and deeply, and ensure healthy growth.
DON’T use broadcast sprinklers.
In addition to soaking the plant’s leaves, which can increase the risk of a fungal disease, broadcast lawn sprinklers are simply inefficient. On a hot or windy day, much of the water distributed by this type of sprinkler can evaporate before it reaches the plant. What’s more, sprinklers are likely to dampen plants’ leaves, and wet leaves can make the plant prone to mold and disease.
DO water outdoor container plants at least once per day.
Soil in container gardens and flowerpots dries out more quickly than soil in a garden plot or flower bed. The smaller the container, the more frequently you need to water the plant inside it. Soak potted plants’ soil in the morning, and, if the mercury in the thermometer climbs to 90 or above, give it another soaking in the afternoon. Alternatively, outfit the pot with an automatic plant waterer, which is basically a hollow spike attached to a water bottle or bulb. When the spike is inserted in the pot, water slowly seeps into the soil, offering the plant a steady supply of moisture.
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DON’T forget that trees need water, too.
Newly planted trees and shrubs should be thoroughly soaked with water two or three times per week for the first month. After that period, water weekly during their first growing season. Established trees and shrubs that are at least two years old only need to be watered once every two weeks during the growing season when rain is scarce.
DO use a wand to water container plants.
A watering wand extends the reach of your arm, allowing you to direct water at soil level in overhead hanging plants and in short, ground-level flowerpots without having to stretch or stoop. You’ll save yourself some backaches to be sure—and you’ll conserve water by aiming only as much water as you need at the base of the plant.
DON’T water container plants with a jet-type spray nozzle.
Pressurized nozzles are great for washing off driveways and sidewalks, but the powerful spray that they deliver can damage tender foliage and blossoms. It can also disturb the soil around the roots of a container plant. If you don’t have a watering wand, just remove the nozzle from the garden hose, hook the hose into the hanging pot or container, and let the water run out slowly.
DO check the soil’s moisture level.
Garden plants can suffer when the soil dries out. On the flip side, they don’t like “wet feet,” meaning they also suffer if their roots are sitting in water and not getting sufficient oxygen. On a hot, windy day, the soil’s surface may appear dry, while the ground beneath is still moist, so it’s essential to perform a quick check to ensure you don’t overwater. Keep a wooden dowel handy and insert it a few inches into the garden soil and then pull it out and check it. Moist soil will stick to the dowel, but if it comes out clean, the soil is dry, and it’s time to water.
DON’T rely on rain.
Most garden plants, flowers, and shrubs flourish when they receive at least 1 inch of water per week, although they may need more during hot, dry spells. In many parts of the country, there isn’t always enough rainfall for plants to thrive, so don’t count on it to keep your plants healthy. Using a rain gauge in the garden can help you monitor how much weekly rainfall you’re getting. If the gauge indicates that you’re getting less than 1 inch of rain, supplement by watering.
Watering Indoor Plants
DO use a watering can for houseplants.
Trying to water a leafy houseplant from a drinking glass or carafe is just asking for water to spill out over the rim and onto your table or windowsill. Not only does a watering can‘s long spout eliminate spills, but it also allows you to direct water right at the base of the plant even if you’re watering plants that hang overhead.
DON’T water houseplants with treated, softened water.
Home water softeners impart sodium into your tap water, which, over time, can negatively affect the mineral makeup of a houseplant’s soil. Depending on your plumbing, your water softener may connect only to the hot water faucets or to all the faucets in your home, both hot and cold. If it’s the latter (or you aren’t sure), stick to filling your watering can at an outdoor spigot to minimize the amount of sodium you introduce to the soil.
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DO choose the right soil.
Houseplants will benefit from an indoor potting mix that’s made for the particular type of plant being grown. Avoid filling houseplants’ pots with soil that you brought in from your outdoor garden because it can contain pathogens, insects, and fungi. Leave plant diseases and gnats outside where they belong! Another good option for indoor plants is to use a soilless houseplant mix that contains a mixture of peat moss and perlite or vermiculite. These mixes won’t pack down so roots can reach deep, and they often come with fertilizer that will boost plant growth.
DON’T use a potting mix that’s too water-retentive.
Most houseplants need a well-draining potting mix that doesn’t remain soggy for hours after watering. When shopping for potting soil for houseplants, look for products that contain either coconut coir, vermiculite or perlite. All three ingredients are used in potting mixes to help aerate the soil and encourage good drainage. For best results, use a potting mix that does not contain more than 1 part peat moss.
DO invest in a soil moisture gauge.
Most soil moisture gauges cost less than $20. These gadgets help gardeners determine whether their soil is dry, moist, or wet as many as several inches deep by the roots. (In our researched guide to the best soil moisture meters, our contributors conducted hands-on tests to find the best meters on the market.) Large houseplants in small pots absorb water more quickly than small plants in large pots. When you use a moisture gauge as opposed to following a watering schedule, your plants will get the water they need, when they need it.
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DON’T put houseplants in pots that don’t have drainage holes.
Most houseplants need well-drained soil in order to grow and thrive. If water cannot drain out through the bottom of the pot, the plant’s roots will sit in water and will be prone to rotting. Check the undersides of your plants’ pots, and repot any without drainage holes into more appropriate containers.
DO water less in winter and more in spring.
In winter, days are shorter and indoor houseplants receive less ambient light through windows. When this happens photosynthesis (the process in which a plant turns light into food) slows down and the plant enters a resting phase, during which it needs less water. As spring approaches, however, longer days signal the plant to start growing, at which point its water needs increase. Adjust your habits for watering plants accordingly so as not to cause distress or thirst.
DON’T forget to dump the water collection tray.
When watering indoor plants, excess H2O will drain into the collection tray under your houseplant almost immediately. Don’t pour the water out right away—the plant may reabsorb some of it within the next few minutes. After about half an hour, go ahead and dump it. Allowing a plant to sit in standing water increases its risk of root rot, which could potentially kill the plant.
DO wick your plants while you’re away.
Even the healthiest houseplants will suffer from not being watered for a week or two when the family goes on vacation. Avoid setting them in the tub or sink filled with a couple of inches of water, or they could perish from wet feet. Wicking is a simple way of ensuring the plant gets enough water without flooding it. Place a large jar of water next to the plant. Cut a section of cotton rope or even a strip of absorbent fabric long enough to reach from the plant to the bottom of the water jar. Poke one end into the top of the soil and insert the other in the water jar. The rope acts as a wick, slowly transferring water to the plant while you’re away.
DON’T overwater.
Overwatering is one of the main causes of houseplant failure. Houseplant newbies have a tendency to water houseplants too often, thinking that’s just what they need. Overwatering, however, increases the risk of root rot and fungal disease. If you see droopy stems, wilting leaves, a whitish coating (fungus), or fungus gnats in the home—pests that thrive on consistently wet soil—it’s a good bet that you’re watering plants too much.
On the other hand, when the bottom leaves on your houseplant dry out and drop and edges of the leaves elsewhere on the plant become crisp and brown, it’s probably not getting enough water. Again, refer to the soil moisture gauge for that happy medium.
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FAQs
Indoor houseplants add beauty and bring a touch of natural décor to the home, while outdoor garden plants enhance landscapes. However, keeping them healthy and lush means giving them adequate water. Those who are new to gardening or keeping houseplants will likely have some questions.
Q. 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.
Q. How much water do plants need a day?
Plants don’t need daily watering. Instead, water deeply but less frequently. Deep waterings allow the water to seep beneath the roots, which encourages the roots to grow downward.
Q. How do you properly water plants?
The general rule is to water plants at ground level rather than using a sprinkler, which can leave water on the foliage, increasing the risk of harmful fungal growth.
Q. Is it better to water plants or depend on rain?
Outdoor plants love natural rain, but if it doesn’t rain at least 1 inch per week where you live, considering watering to supply enough moisture for healthy plant growth.
Final Thoughts
In addition to light and oxygen, plants need water to thrive. Good watering practices will result in healthy plants—both indoors and out—that add to a home’s décor or landscaping. Regular watering is also essential for producing healthy fruits and vegetables in the garden.