Figuring out how to water houseplants correctly can be as much of a mystery as how to eat an entire cake without feeling like some kind of savage afterward. Or how to keep your teeth calm when your jackass coworker keeps trying to tell you what to do.
The truth is most houseplants die due to overwatering. But that’s actually good news. It means you can literally save lives just by being lazier. So stop watering your plants every day and start spending more time drinking wine on the couch. Man, wouldn’t it be nice if that were the solution to all of life’s problems.
If you’d like to start your laziness training now, just stop reading and go do that. But if you want a few more details about how to help your houseplants thrive, read on, friend.
Table of Contents
How Much Water Does an Indoor Plant Need?
It depends. I know that answer sucks, but it really does. Some houseplants will guzzle water, while other low maintenance indoor plants prefer just a sip every few weeks. As a general rule of thumb, plants with chunky leaves (like aloe and other succulents) need less water, while plants with thinner leaves need more.
But that’s just a general guideline, not absolute gospel. There are a few other factors to consider.
The Pot Matters
Most plants you buy come in grower’s pots (cheap black plastic pots). These are meant to be temporary containers, but for a lazy houseplant owner like me, temporary could mean a year or more.
On a scale from breathable to not breathable, plastic pots fall somewhere in the middle. That’s compared to something like terra cotta, which is very breathable and therefore will lose water faster. Or thick ceramic, which is less breathable and therefore will lose water slower.
Thus, if you’re a lazy bum like me and you leave your houseplants in the grower’s pots forever, they will need an “average” amount of water based on that factor. But if you plant them all in fancy terra cotta pots, they’ll need to be watered more often.
The Potting Mix (Soil) Also Matters
Some indoor plants are potted in what basically amounts to chunks of bark or very sandy soil, which means water flows through quickly and doesn’t get deeply absorbed (a good thing for plants like orchids and succulents). But most potting mixes are designed not to dry out too quickly while still staying fluffy enough that the plant’s roots have access to oxygen.
Either way, if the potting mix is super dry or chunky, it will struggle to absorb water. So if water runs out of the drainage holes surprisingly quickly, it’s probably just passing right through without being absorbed. And if your plant is not an orchid or succulent, it probably won’t be happy with that.
Think about this conundrum like a dehydrated human. Dump a bunch of water down their throat too quickly and they’ll probably just barf it up. Instead, you need to give them a long, slow drink. Then maybe another long, slow drink a few minutes later. Most plants actually prefer deep drinks rather than tiny sips.
Then There’s Light, Temperature and Humidity
Just like humans need more water when it’s hot and sunny, so do plants. If your houseplant sits in a warm, sunny spot all day, it’s going to need more water than one that’s been forgotten in a cool, dark corner of your guest room (totally not speaking from experience). And since humid areas (like your bathroom) have more moisture in the air, plants that live there will need less water.
There’s Also Dormant Phase Versus Growth Phase
Houseplants are like bears because they’re kind of scary (until you get to know them) and most of them hibernate over winter (living the dream). Obviously they won’t need much water while hibernating, especially compared to when they’re growing like crazy, sending out new leaves practically every day.
Just Answer the Damn Question – How Much Water Does My Houseplant Need?!
Basically, just keep slowly watering until water comes out of the drain hole. This ensures that all the roots get wet. Then, don’t water your houseplant again until the top inch or so of soil gets dry.
How Do I Know When to Water My Houseplants?
The quick and dirty (heh heh) way is to stick your finger into the soil up to the first knuckle or so. If the soil feels dry, water it. If it still feels damp, wait. That’s literally the secret to watering houseplants correctly.
Another way to tell when to water your houseplant is to lift the pot and feel how heavy it is. Since wet soil is heavier than dry soil, a heavy pot means it probably doesn’t need water. But if the pot is as light as a feather, your plant more than likely needs a strong drink.
Some signs that your houseplant needs water are wilting, yellowing leaves and leaves falling off. But yellowing leaves can also mean too much water. I know, so confusing. (You can read more signs that your plant needs water here.)
Okay, but listen. Here’s the FASTEST EASIEST WAY to tell if your houseplants need water. Use a moisture meter! Yes, they actually make a thing that solves this problem once and for all (mostly). And they’re pretty inexpensive, too.
How Do You Use a Plant Moisture Meter?
Hold the gauge part in your hand and then stick the pokey part into the soil about three-quarters of the way down into the pot. The pokey part (aka probe) will measure how much moisture is down there around the roots of your houseplant. The gauge part usually has a scale from one to 10, with one being super dry and 10 being super wet. It might also have a color range from red (dry) to green (average) to blue (wet).
Now, the only tricky bit about using a moisture meter is that just because it’s in the red zone doesn’t necessarily mean the plant needs water. Plants like cacti love being dry, so they should mostly stay in the red zone.
But for most houseplants, you’ll want them to be solidly in the green zone. If they get into the red zone, give them a drink. If they get into the blue zone, don’t water them again until they move into the red or low green zone.
Be sure to use the moisture meter to check your indoor plants every few days as you get to know them. After a few weeks you’ll have a good idea of how often they prefer to be watered and can check them less often (aka spend more time binging Netflix from under your blanket mountain).
Pro Tip: Since houseplants don’t have worms or other creatures to aerate their soil, you’ll need to do it yourself from time to time. You can use your moisture meter to do this. Just poke it in and out of the soil a few times in various spots around the plant and voila, your soil is aerated!
What is the Best Way to Water Indoor Plants?
You might think this is a dumb question – just dump some water in there, right? Like with a watering can, right? Well, sort of. If you’re top watering, then yeah, pretty much. Just use a watering can with a long spout (like this one) so you can direct water down around the soil and avoid wetting the leaves. Wet leaves lead to disease and pests, and no one wants that mess.
But there’s a bit more to it. You probably enjoy a nice, long bath. But if you stay in the tub too long, you turn into a pruned up mess. Same with your plants. They don’t like sitting in their water for too long. And it’s actually a great way to invite root rot, the el niño of houseplant maladies.
So if your pot sits in a saucer or one of those little plastic drain pans, check on your plant about 30 minutes after watering and dump any lingering water from the saucer. If your pot sits inside a decorative pot without a drain hole, do the same thing and dump any water from the outer pot after about 30 minutes.
What is Bottom Watering?
Sounds kinky, right? But it’s actually a method of watering in which a plant absorbs water from the bottom instead of the top. It’s a great way to encourage your houseplant’s roots to grow deep, which makes for a stronger plant. It’s also a way to avoid getting the leaves wet, which as I mentioned above, can invite disease and pests.
To bottom water your plant, just add water to the saucer (or the outer pot if you’ve got a pot within a pot situation). Let it sit for 10 or 15 minutes, then check the soil with your finger or moisture meter to make sure it has absorbed enough moisture. If not, give it another 10 or 15 minutes and check again. Just make sure you don’t forget about it and leave it soaking all day!
If you decide to bottom water your houseplants, you should still top water occasionally (once every month or so) to flush excess salts and other built up minerals from the soil.
Is it Bad to Water Houseplants at Night?
In a word, yes. When you water your houseplants, moisture collects at the soil surface, under the leaves. If it’s daytime, a lot of this moisture will be evaporated by the sun. And since soggy leaves invite diseases and pests, this is a good thing. Moisture stays around the roots of the plant, not the leaves.
Watering at night leaves that moisture build-up under the leaves. No bueno. But if it’s the only time you have to water because life is crazy, go for it. Try bottom watering if you can and make sure there’s plenty of airflow around your plants.
What Kind of Water Should I Use?
Only the purest snowmelt from the summit of Mt. Everest.
But for real, some plants will act like that.
For most plants, just use room temperature tap water that has been allowed to sit out for awhile. In other words, just fill up your watering can and let it sit until next time you need to water. That will give the water a chance to come to room temperature (cold water can shock your plant’s roots) and allow any chlorine your city adds to the water to dissipate.
If you really want to be a plant goddess, set up some kind of rainwater catchment system (as in, put a few empty bowls or whatever outside) and use that to water your plants. Rainwater has nutrients that tap water doesn’t (remember the water cycle?), so it makes plants extra happy.
Get to Know Your Plants
Figuring out exactly how to water your houseplants can be intimidating. But it only takes a few weeks to start getting to know your particular indoor plants and what they like.
Just remember to check the soil (either with your finger or a moisture meter) and don’t give your plant any more water unless it’s dry. That one simple trick will literally make you the Michael Jordan of watering houseplants. But without all the running and jumping and basketballing. Being a houseplant goddess is way easier than being a professional athlete.