Calatheas are lucky that they’re so beautiful, or few indoor gardeners would bother trying to grow these fussy plants. One of the trickiest aspects of their care is providing the right amount to drink. This guide will explain how you can tell your plant is thirsty and how to satisfy its exacting requirements for hydration.
The best way to determine whether a Calathea needs water is to monitor the soil. When the top two inches of the potting mix have dried out, it’s time to top off your plant with a thorough watering. You can also use a wooden chopstick or moisture probe to test the soil right by the plant’s roots, offering even more precision. Calatheas prefer their growing medium consistently damp but not soaking wet.
If you let your Peacock Plant go too long without watering it, the foliage will display signs of distress, like wilting, curling, and discoloration. If these symptoms are combined with dry soil, it’s a good bet that your plant is pouting because it’s thirsty. Refer to our tips below if you’re wondering whether your Calathea is dehydrated or suffering from some other problem.
How Much Water Do Calatheas Need?
It’s easy to assume that because Calatheas are rainforest plants, they like to be constantly showered with life-giving water. The real picture is a little more nuanced.
The jungles where Calatheas prefer to make their home do feature frequent rain showers and high humidity. However, the earth in those tropical forests also drains much more quickly than it does in your average indoor plant pot.
So a Calathea’s roots prefer a delicate balance: enough water to drink, but not so much that the environment becomes swampy. Give it too little, and the plant will throw a tantrum, its growth slowing and its leaves becoming brittle and shriveled. Too much water can be even worse. Dank, mushy soil can lead to root rot, a deadly condition that can destroy a previously healthy plant in just a few weeks.
Finding the happy medium requires paying careful attention to the condition of your Calathea and its overall growing conditions. The amount of water it needs in any given week can change based on factors including temperature, humidity, light, pot size, and the plant’s growth rate.
So instead of watering on a rigid timetable, watch out for the following signs that it’s time to give the plant a drink:
Number 1: The Soil is Drying Out
This is the first and most important signal that it’s time to water your Calathea. The best time to water is when the plant isn’t yet thirsty, but the soil is.
Don’t wait for the potting mix to dry all the way through, turning into a solid cake that’s peeling back from the edges of the pot. Instead, water when the soil is dry at the top of the container but still mildly damp near the roots.
The simplest way to check is with your finger. Poke it about two inches into the surface of the potting mix; if it feels dry, it’s time to water.
You can get more precise by using a long, thin probe to get down into the space by the roots. A plain wooden chopstick is a perfect tool for this purpose. Insert it into the soil until it’s near the base, wait for a few minutes, then pull it out and assess how damp the end is. If it’s soaked through, give it another few days and check again. If the chopstick is only mildly damp, go ahead and give your Calathea some refreshment.
One other option is to use a moisture meter. You’ll need to practice with it a bit to get a sense of how the readings correspond to the actual moisture content, because moisture probes can be thrown off by factors like a high concentration of mineral salts in the potting mix.
Number 2: Drooping Stems
Calatheas are infamous for pouting when anything about their environment isn’t up to their standards. One example is the way that they slump and slouch when their water level begins to run low. Virtually all green plants do this to some extent because their ability to stand upright depends on their cells being inflated with fluid, but Calatheas are especially prone to dramatic shifts.
Remember that Calatheas naturally lower and spread their leaves during the daylight hours, part of the daily cycle they share with their cousins the Prayer Plants. Be careful not to mistake their ordinary unfolding for drooping caused by thirst.
Number 3: Curling Edges
When a Calathea leaf becomes dehydrated, it will start to curl inward from the sides toward the central vein. This is a defense mechanism intended to reduce the amount of water vapor escaping from exposed leaf pores. If the foliage on your Calathea begins imitating an old-fashioned scroll, you can be sure that it’s low on moisture.
This isn’t always due to underwatering; dry air can cause the same effect. Just as you should monitor your Calathea’s soil, it’s also a good idea to keep an eye on the ambient humidity – you may want to invest in an inexpensive hygrometer for this purpose. If the humidity is less than 50%, your plant’s curling leaf edges may not be due to underwatering at all. For more information on Calatheas and humidity, read this article.
Number 4: Leaves Stop Raising at Night
As we noted earlier, a healthy Calathea will raise its leaves each night to stand upright, unfolding them again in the morning. This behavior, often referred to as “praying,” relies on a special joint below each leaf called a pulvinus that can swell or contract by taking in or releasing water. If a Calathea has no water to spare, its daily movements may weaken or stop entirely.
Don’t be concerned if only one or two leaves fall still. That can happen as a result of leaves naturally aging out or damage to the pulvinus in an individual stem. But when the entire plant loses interest in reaching for the sky at night, something may be off in its growing conditions.
Note that the most common reason for a lack of praying in Calatheas is too much or too little lighting, so check for that before immediately dousing it with water. And always check the soil if you suspect that underwatering is the problem. For more on your Calathea’s praying habits, take a look at our article on the subject.
Number 5: Yellowing or Browning Foliage
This is a tricky one because Calathea leaves can become discolored for a variety of reasons. All of them come down to a lack of moisture reaching the foliage, but that can just as easily be caused by root malfunction as by underwatering. Always refer back to the soil if you suspect you’ve underwatered your plant. If the potting mix has dried out, that’s the likely culprit.
On the other hand, if the soil is still moist, the leaf discoloration you’re observing could be caused by:
- Overwatering
- Root rot
- An excess of mineral salts (especially likely with browning tips)
- The plant outgrowing its pot
- Sunburn
Try to rule out these other issues before watering a Calathea that appears thirsty.
How to Water Your Calathea
Once you’ve determined that your plant needs to be watered, it’s important to be thorough. Moisten the soil evenly and give your Calathea enough water that some of it drains out the bottom of the pot.
Use room-temperature water; Calatheas are sensitive to temperature extremes. And despite what some trendy houseplant guides may advise, don’t ever water these tropical divas with ice cubes. Tap water may also be a bad choice, as it often contains high concentrations of minerals and other chemicals that can stress the roots of your sensitive plant. Rainwater or distilled water are both better options. (Find more about the benefits or watering with rainwater here.)
We’ve provided a more detailed breakdown of proper watering habits for Calatheas that you can read right here.
Final Thoughts
When in doubt about whether your Calathea needs water, check the soil first. Proper hydration begins at the roots. As long as you keep your Calathea’s growing medium damp but not soggy, this picky plant should have all the moisture its thirsty leaves crave.