Watering potted plants seem like such a simple task, however if it is not done correctly the plant won’t survive.
In fact, of all the care given to potted plants, watering is probably the one cultural practice that causes the most problems. The most common cause of early plant death is generally considered to be over-watering.
Fortunately for us, ninety five percent of the plants out there will be happy if you follow the simple guidelines in this article.
But first we have to agree that either too frequent or too infrequent watering is detrimental to the plant – regardless of the requirements of water.
This raises the question; how do you know how much water to give your plants and how often?
Well, let’s find out how to water potted plants and keep them happy.
How to determine if your Plants need Watering
Potted plants tend to dry out more quickly than their in-ground counterparts.
If you’re new to growing houseplants, poke your finger an inch into the soil to make sure it is dry below the surface.
Alternatively, there are inexpensive watering gauges you can find at many hardware and home or online stores like Amazon that help you learn when a plant is dry.
Some of the more elaborate ones even include a computer chip and database of common plants, integrating a specific plant water needs with the current soil moisture.
If you determine a potted plant is dry, lift it to feel the weight. Doing this with various pots you’ll soon develop a feel for when to water, just by the weight of the pot.
How to Water Potted Plants
The best way to water is to use a watering can with a long, narrow, spout.
This allows the placement of water directly on the soil. Watering plants with dense foliage will be more difficult if this type of watering can is not used.
Try not to put the water on the leaves and crown, as rot diseases are more likely to occur if water is continually poured on the crown.
For watering, lukewarm water, or water near room temperature is best.
This is especially important during the cool season and winter when water may come out of faucets icy cold. This can shock roots, particularly of tropical plants, and lead to root disease and death.
Bottom watering is a practice where the plant is set in and absorbs water from a saucer or container filled with water.
Plants regularly watered from the bottom should occasionally be watered from the top to get rid of excess salts in the soil. Make sure plants don’t continually sit in water—just for a short time until some is absorbed by the soil.
Some plants enter rest periods at some time of the year.
Resting plants may use less water so are more likely to be over-watered. If a plant slows or stops growing in late fall or early winter, it may be entering a rest period.
Some plants naturally require less water.
These include cacti and succulents (those plants with thick and fleshy leaves, ponytail palm, Chinese evergreen, and snake plant). I have some “indicator” plants that I watch, such as the peace lily or spider plant, which tell me it’s time to water when they start to wilt.
The best advice is that if in doubt about whether to water or not, don’t. It is better for plants to be a bit dry, than too wet.
How to water potted plants automatically
Keeping your plants watered while you are away on vacation can be a hassle, especially for plants in containers. If you can't find a neighbor to give them a daily dousing for you, you might want to try one of the automatic methods.
To do this, set up a drip irrigation system for watering outdoor potted plants. This allows for slow, even watering that the soil can absorb before it all runs through the pot and out the drainage holes.
The right time to water potted plants.
Ideally, early morning or early evening is the optimal time to water your containers, as this will give the plant some time to take up the water before the heat of the day kicks in but will also allow excess water on the plant to evaporate quickly so that the plant is not vulnerable to fungus.
Furthermore, roots are more receptive to watering in the morning and the evening and less so in the midday sun.
However, it's not a good idea (if you can prevent it) to water in the evening, because when you let water sit on the leaves overnight, your plant is more likely to contract some plant diseases and fungus, like powdery mildew.
That said, if you get home from work and your plants are dry, even if it's in the evening, give them a good long drink.
How much water to give plants
The required amount of water may vary from species to species. When watering, apply enough water so some comes out the drain hole at the bottom of the pot.
This flushes out salts that can lead to root injury, and ensures you are not merely watering the surface of the soil.
Do not let plants sit in excess water, though. It will be reabsorbed and, thus, the salts dissolved in the water will be reabsorbed.
Plus, the plants will stay too wet, leading to root rots.
If you have a saucer under the pot, make sure after a short time (half hour or so) to empty the water out. This allows water to be absorbed from the bottom—especially important if the soil is really dry.
If you have a pot within a more decorative pot—the latter without a drainage hole—make sure the outer pot doesn’t fill with water.
Lastly, understanding how much water for container plants is appropriate is usually a matter of trial and error until you know your particular plant’s preferences.
How often should potted plants be watered (Watering Frequency)
The two main aspects of watering to be considered are frequency of watering and amount of water applied.
The watering frequency is simply how much time passes between waterings.
The frequency will vary over the course of the year.
It really isn’t that difficult or rocket science once you consider environmental factors, and the individual plant needs.
Avoid watering on a fixed schedule such as every week or every five days.
A fixed schedule does not necessarily give plants water when they need it. In fact, watering on a fixed schedule may mean plants are over-watered at one time of the year but under-watered at other times.
It is a good idea to get on a fixed schedule to check them for water, once you know your plants and how fast they dry out.
With few exceptions, plants should be watered when the soil feels dry to the touch. This means the frequency of watering will vary with the rate at which the soil dries out.
Factors that affect watering frequency
The type of soil used as a potting medium affects watering, as does light exposure, temperature, and humidity.
Just as many environmental factors change with the seasons, so do the water needs of plants. Plants in a warm room, particularly near a wood stove or with forced-air heat, will dry out sooner than those without these conditions.
Hanging plants often dry out more quickly than those in pots on a table.
If the air is dry, placing plants on a tray of pebbles kept moist will help them retain moisture longer. Using a room humidifier nearby helps too.
Watch the weather too, and try not to water plants by windows when it is very cloudy outside, or forecast to be cloudy and rainy.
They won’t get sun to help dry them out, and so may stay too wet for too long.
A good potting soil will have good aeration and water drainage, yet will hold onto some water as well. These often contain a large amount of peat moss.
Some of the newer “organic” mixes drain very well, but hold little water. Plants in these mixes will need lots more watering, or re-potting into a peat moss-based medium.
At least with soil media that drain exceptionally well, there is less chance to over-water!
Important takeaway tips on how to water potted plants
- Be sure your pot has drainage holes - Proper drainage is essential to happy roots, and happy roots are essential for happy plants.
- Water only when the top of the soil is dry – Avoid the risk of over-watering.
- Don't let the soil dry out completely - Most potting mixes become tough and won't absorb water efficiently if you let them completely dry out.
- Water until water comes out of the drainage holes - many of the plant's roots will be down towards the bottom and you want them to be able to get water too.
- Don’t allow your pot to sit in standing water - Pots sitting in water will keep the soil in the pot too wet, allow excess
- Apply a layer of mulch or rocks to the soil surface to slow moisture loss.
- Water the soil, not the leaves - It turns out that some plants - ones with hairy leaves - are susceptible to sunburn if you get water on their leaves in the sun.
Watering potted plants might seem like a very easy thing to do. But you’d be surprised at how many people get it wrong.
Most problems experienced in container gardening are associated with bad watering habits.
Lucky for you because you’ve just read how to water potted plants the right way. You just need to put the lessons learned to action and your plants will thank you for it.
Let me know your thoughts.