How to water indoors plants is probably the most important thing every houseplant owner needs to know.
That’s because watering can cause serious problems that can ultimately destroy an otherwise healthy houseplant.
In this article, I will cover the different things you should know about watering plants indoors.
Much like sunlight, your plants need water. And, too much is just as bad as too little water.
In fact, overwatering is the most common reason houseplants die (causing root rot).
That said, different plants require different amounts of water. But, the majority of them enjoy moist (not wet) soil.
However, some are designed to be more drought-tolerant. Often these are plants that have evolved to be so because of their environment. As such over time, they’ve adapted in order to survive.
One popular example is are cacti. Because they grow in dry conditions, they’ve evolved to hold water for long periods of time. So, they can go up to a couple of months without watering.
Other succulents as well as thick-leafed plants are also able to withstand little water for varying lengths of time.
How Do Plants Absorb Water?
Plants absorb water through their roots.
It’s worth noting that different plants have varying kinds of roots. As such, how they absorb water also differs. But, they all provide the same function.
Water and nutrients are absorbed from the soil via root hairs that grow at the tips of the roots. From there, they travel up the plant’s vascular tissue, which includes the xylem, until they reach the leaves.
Finally, they’re released back into the air as vapor through the openings on the lower side of the plant’s leaves.
If you remember your high school biology, this process is called transpiration.
How Much Water Do Houseplants Need?
In general, the amount of water your plant needs will vary based on the kind of plant you have.
But, there are a few important things to know when it comes to watering your indoor garden.
Watering Needs of Indoor vs. Outdoor Plants
One of the biggest differences between plants in your garden and houseplants is the amount of soil present.
- Outside your plants’ roots are free to extend down the earth in order to find water and nutrients.
- Inside, they’re more likely to be housed in pots and containers. This limits the amount of potting soil they can search for nutrients and water.
Why is this important?
The bigger the container and the more potting soil there is, the more water it will be able to hold. That’s because water molecules cling onto the soil. As such, the soil works somewhat like a sponge does in soaking soapy water.
Air and Water Balance
But, it’s not all about water.
When you pot a plant, you’ll likely notice that there are pockets of air in between the soil particles. This space allows your houseplants to get air in the form of oxygen, which is another important element for plants to survive.
When you water your plants, the liquid fills in these air pockets. And, over time, your plant absorbs the water, and these air spaces open up again.
This is why a regular water schedule is essential. You’re able to provide your plants with both water and air through the continuous cycle of filling and absorbing water.
This setup allows your plants to get the water and oxygen they need to grow.
Should You Water Little by Little or A Lot at a Time?
Most of us have been taught that moderation is good. As such, this concept is likely to work as well with watering your plants, right?
So, the question is, should you water a little a day regularly, or fill your plants with a lot of water and only water again when it starts to get dry?
If you answered the latter, you’d be correct.
Plants prefer a lot of watering per session as opposed to just a little at a time.
Thus, you should water your houseplants very thoroughly each time you do. This means watering up until it starts draining from the bottom of your pot.
Doing so encourages your plants’ roots to dig deeper down. This allows it to develop a stronger root system.
In contrast, watering only the top makes your plants’ roots “lazy”. That’s because it will only work to get to the section that’s watered. As a result, the roots don’t develop deep into the soil. So, you don’t get as strong a foundation.
In addition to being easily toppled or pulled out, a shallow root system also misses out on the nutrients that are at the bottom of the container.
How Your Container Affects How Often You Water
Above, I mentioned that the amount of soil indoor plants get is limited by its container.
In addition to that, the size of the container also determines how much water it can hold.
- Small containers hold less water. As such, you’ll be watering more frequently.
- Large containers can hold more water. Thus, it takes a longer interval between watering sessions.
But that’s not all.
The material your container is made of also matters.
- Metal and Plastic Containers. These are made from non-porous materials. As such, they don’t allow water to seep out in any other direction besides the top.
- Clay, Concrete and Wooden Containers. These materials are porous. Thus, there are tiny spaces or holes allow water to escape. As a result, you’ll need to water more frequently.
That said, most of us choose containers based on how they look. But, these factors are worth considering if you don’t like having to keep watering your plants.
This is especially true with larger plants and trees. That’s because you’ll likely feel the difference. This isn’t much of a worry for smaller plants.
How Much Light Your Houseplants Are Getting?
The direction in which your plants are facing also affects how much water they need.
- Windows facing north receive less light. As such, it isn’t as warm. Lower light also reduces the rate of photosynthesis as well as transpiration. Thus, you won’t need to water as much.
- Plants with southern exposure will require more watering. That’s because the higher temperature and more sunlight produces the opposite effect.
- Plants facing the west will need more water than those in the east because the afternoon sun is much hotter than the morning sun.
Last but not least, there’s artificial lighting.
Here, the kind of light you use will affect the amount of water your plants need. In general, most artificial lighting will run longer than sunlight. That’s because they’re lower quality light.
Also, they use electricity which produces heat as well. So, the closer the light to your plants, the more often you’ll need to water as well.
Your Plants’ Water Needs Vary By Seasons
One of the things you’ll quickly realize is that your houseplants need more water during the warm months and less during the colder ones.
Like you and I, how much hydration plants need varies depending on temperature.
Warm climates cause more evaporation to occur. As such, the water needs to be replenished more frequently.
Also, the spring and summer months have longer days. In contrast, winter months have longer nights.
Longer days mean more light. As such, more photosynthesis occurs.
During photosynthesis, plants use light, water, and carbon dioxide to produce food (nutrients), energy and oxygen.
So, they use up and need more water. Therefore, most plants grow more during the spring and summer.
It is also why it’s important to adjust the amount of water-based on the time of year.
How Often Should You Water Your Houseplants?
Learning when to water your plants can be tricky. That’s because there are so many factors that are involved.
We’ve touched on a few above.
The real important question is, when do you water your plants?
Ideally, you can develop a regular schedule. Of course, this will change depending on the time of year as well.
But, over time, you’ll know when your plants need watering simply by looking and feeling it. Here are a few ways.
- Visual inspection. Once you’ve gotten used to your plants, you’ll be able to tell even from a distance. But, in the beginning, check the texture and color of the soil. Hard, cracked soil or one that’s light in color means it’s time to water. Ideally, you want your soil to be moist, not dry or wet.
- Stick your finger in the soil. If your finger isn’t able to penetrate the top of the soil or much below the surface, then the soil is dry. If it feels very wet beneath the surface, there’s likely too much water.
- Lift the container. This takes experience to get the feel of it. But, you’ll be able to distinguish the amount of water based on the container (and plant’s) weight. Water makes soil considerably heavier. So, when it gets dry, it will be a lot lighter.
Signs You’re Overwatering Your Plants
- The soil looks wet
- Brown leaves
- Yellow or brown patches
- Dropping leaves
- Excess water in the saucer under your pot
- Fungus and mold
- Root rot
Signs You’re Underwatering Your Plants
- The soil is dry
- Not producing as many flowers as usual
- Stunted growth
- Leaves and flowers dropping
- Leaves change color
- Leaves curling up
How to Water Your Houseplants Properly
Everyone knows how to water plants, right?
The good news is, when it comes to watering your plants there are many ways you can do so. And, it’s difficult to go wrong. Here are a few options.
- Watering can. This is probably the most popular for indoor plants. Depending on how big your plants are, you’ll want one that’s appropriately sized. Large watering cans will spill a lot on smaller plants. Small cans will mean refilling more often.
- Indoor hose. This is the simplest. It’s also the fastest, especially if you have bigger plants. They’re likewise very affordable and work just like your garden hose.
- Wand attachment. If you have hanging plants or small pots, you may need a wand attachment for your hose. This reduces spillage. And, it also makes it easy to water pots and baskets that are higher than eye level.
- Use a basin. If you don’t like spillage, you can place your plants over a basin or something that catches any wayward water. This ensures that you don’t need to clean up afterward.
- Using a plate. If you plan on bottom watering (see below), then you’ll need a plate to hold your plant while it sucks up the water on it.
One indispensable tool I’ve come to love is the baster. Yes, the one you use to baste chicken and turkey in the oven.
This cheap kitchen item works wonders when you have to remove excess water from the top of the soil. You can likewise use it to add small amounts as well.
That said, the biggest key to consider when watering plants are:
- Spillage. You don’t want to make a mess. This is a problem with houseplants because you’re indoors. It isn’t when you’re outside.
- Wetting the foliage. Whatever you do, don’t water the leaves. This makes them prone to fungi which will ruin your houseplants.
Should You Water Houseplants From Top or Bottom?
Either way works. It all depends on how you do it.
- Watering from top to bottom. This is simpler and faster. It’s also the more common way of watering plants for most people. That said, it isn’t as thorough as the bottom to top watering (bottom watering). When watering from the top, make sure that you don’t wet the leaves. And, water enough so that all of the soil is covered. You’ll usually be able to tell when you get there because water will start draining from the bottom of your pot.
- Watering from bottom to top. This is less intuitive. That’s because we’re used to using watering cans and hoses. But, it allows your plant to get a more thorough watering. This works by placing the plant on a dish or container with water. Here, the plant does the work as it absorbs water and pulls it upward. As you might guess, the process takes a lot longer than top to bottom watering (top watering).
Do Indoor Potted Plants Need Drainage?
Another important thing to consider when watering your houseplants is allowing it to drain.
Here, a pot or container with drainage holes is key. This allows the excess water to drain out. It also prevents standing water which isn’t good for your plants.
In case your pots or containers don’t have holes, you can place rocks at the bottom of your pot. This provides space between the bottom of your plant and dripping water.
- Indoor Plant Temperature & Humidity Needs
- Plant Pot Types and Sizes
- Plant Propagation for Beginners
- The Best Potting Soil For Indoor Plants
- How To Water Indoor Plants While On Vacation
- Houseplant Lighting Guide – Indoor Plant Light Requirements
What Temperature Should Water Be?
Refrain from using cold water when watering your plants. The low temperature can shock your plants which can cause them to behave in all sorts of unpleasant ways.
Instead, use room temperature water. This means allowing the water to sit for a while to warm up.
Similarly, don’t use hot water.
Is Tap Water Safe for Your Plants?
You probably already know that water from the tap contains chemicals. What you may not know is that in many places, the local government is responsible for it.
That’s the case with fluoride.
Fluoride in Tap Water
Fluoride is often added to the water system because it helps fight tooth decay.
Unfortunately, this same chemical is harmful to some plants. As a result, directly using tap water for watering your houseplants can cause them to change color, deteriorate or even blacken.
The good news is, there are ways to filter chemicals like fluoride. Among them include:
- Reverse osmosis,
- Distillation filtration
- Activated charcoal
These filters are very effective, removing anywhere from 80% up to 99% of chemicals. Thus, it’s a good idea to use some kind of filter if your tap water is high in fluoride.
Chlorine is another chemical that’s present in much of the U.S.’s water supply. Thus, it’s likely present in your tap water. The U.S. EPA (Environmental Protection Agency) allows treatment plants to use chlorine to disinfect water in order to prevent any possible contamination.
But, it’s amount is limited to 4 milligrams per liter of water. That’s around 4 parts chlorine for every million parts of water.
Just like fluoride, chlorine in high enough concentration can harm certain plants.
When it comes to getting rid of chlorine in your tap, you have a couple of options.
- Use a filter
- Let the water sit for 24 hours. This gives it enough time for the chlorine to dissipate. After that, it will be free of chlorine.
In case you’re not comfortable with using tap water and don’t want to spend money on a filter, you can use rainwater instead.
For one, it’s free.
It also doesn’t contain any chemicals since it’s natural.
The best way to collect rainwater is with the use of a rain barrel. This lets you save on watering your garden.
But, you can likewise leave a few pails or containers outside to fill up when it rains. Just make sure, add a “filtration system”, which is pretty much a cool way of saying screen.
The screen will keep leaves, small critters and other debris from getting into the water.