Overwatering an orchid is easy to do. But why do so many people overwater their orchids? What issues does overwatering cause, and can they be fixed?
What is overwatering in orchids? Overwatering is where the orchid’s roots are exposed to too much water. This can occur if you water an orchid too much, pot it in a mix that holds onto too much water, or keep it in a room with high humidity and low air flow (which stops the mix from drying out). Symptoms of overwatering include first yellow-white roots, then mushy, brown, rotten roots and shrivelled leaves. The leaves shrivel because the orchid ironically gets less water when its roots rot, encouraging the owner to water it even more. It can be fixed unless the rot is too severe by watering correctly and repotting in suitable mixture.
The guide below looks at what makes an overwatered orchid overwatered in the first place—and it’s not just you watering it too much. It details what happens if you water an orchid too much, and each of the symptoms of overwatering, so you know what to look for. It also addresses how you fix an overwatered orchid with a simple three-step process that anybody can follow at home.
What Causes Overwatering in Orchids?
Overwatering is a common mistake that new orchid owners make.
There are all sorts of reasons why overwatering happens so frequently. One is that even once the top of the orchid’s mix is dry, the rest of the mix underneath may still be wet. So if you follow the advice that’s common for other houseplants—that you should water when the top of the mix is dry to the touch—then you may be accidentally overwatering your orchid.
But besides that, orchids commonly come with unsuitable mix that makes this problem worse (meaning it’s not all the new owner’s fault). I’ve seen orchids sold in stores potted in regular soil, which holds onto water far too well for an orchid’s preference. With that in mind, let’s take a detailed look at what causes overwatering in orchids, how much of that relates to what you do, how much of that relates to what you know, and how much of it isn’t even anything to do with you!
Watering Your Orchid Too Often
If you never water your orchid, you’ll never overwater it, either. Overwatering is only possible if you actively water your orchid when it doesn’t need to be watered yet.
You should generally water your orchid every week. This varies depending on how quickly the potting mix dries out, how warm and dry the room is, and how big your orchid is/how many roots it has in its pot. But as a general rule, I water my orchids once per week and that’s just about right for them.
Unsuitable Orchid Potting Mix
If your orchid isn’t in the right kind of potting mix, it won’t dry out quickly enough.
Let’s say you have one orchid potted in sphagnum moss, and one orchid potted in generic houseplant soil. You soak both plants the exact same way, for the exact same time and with the same amount of water. Come next week, the houseplant soil is still damp while the sphagnum moss is dried out on the top. If you look inside the orchid’s pot, the sphagnum moss has retained some moisture, but the soil has retained far more.
If you were to then water them both again, the orchid in the sphagnum moss would be fine. But the one in soil would be overwatered. That’s because the roots haven’t had the chance to dry out a little between waterings. So, even if you water your orchids at the same time and in the same way, it’s possible for one to be overwatered while the other isn’t.
Very Humid And/Or Cool Conditions
High humidity, low air flow and cool air all make water evaporate less.
High humidity lessens evaporation because the air is already full of water. Water, like in the context of osmosis, wants to evaporate from somewhere that has a high concentration of water to a low concentration. It’s the same way for lots of things, like heat. This means that the more water is in the air, the less water can evaporate from a water source. Your room may be humid because you live in a humid area, or because the room contains something that gives off water vapor.
Air flow works together with this principle to increase evaporation. The air around the water source is more humid than the air elsewhere; air flow moves this humid air away and replaces it with less humid air, allowing even more water to evaporate. Warmth further makes evaporation more likely, because evaporation is dependent on energy, and more warmth means more energy in the water.
All of this means that if you keep your orchid in a humid but cool room with little air flow, its mix won’t dry out between waterings. If you then water it again before it’s fully dried out, it will experience overwatering.
Symptoms of Overwatering in Orchids
Overwatering can easily go undetected. It has symptoms, but they aren’t noticeable unless you think to look for them, and unless you can recognize them when you see them. Since overwatering affects the roots more than the rest of the plant, the symptoms are mostly related to things inside your orchid’s pot, which you won’t see unless you go looking for them.
So, what does an overwatered orchid look like?
Overwatering doesn’t cause immediate health issues for your orchid. It’s perfectly possible for your orchid to be overwatered, but then make a fully recovery.
The first sign of an orchid root being somewhat overwatered—but not to the point where it’s rotting—is for it to become a pale yellow color, bordering on white. This white color is distinct to the normal grayish-white color of an orchid root; rather, it’s more a bright, very pale yellow off-white color.
This issue occurs because the root has been forced to take in more water than it normally would. Wild orchids go through periods where they have lots of water, and periods where they have very little water. They therefore have to take in as much water as possible sometimes, so that they can be ready for the next dry period. But your orchid doesn’t know that it will keep getting water; it doesn’t know you’re there watering it. So it takes in all that water, but then… More water comes. And more.
The pale color is caused by chlorophyll, or more accurately, a lack of it. Orchid roots have chlorophyll in them, unlike the roots of other plants. That’s because the common orchid species like phals grow on the sides of trees, where their roots have access to sunlight, unlike other plants which don’t. When the root swells up and absorbs more and more water, the proportion of other things in the root go down at the same time; there’s therefore less chlorophyll per gram of root. The less chlorophyll there is relative to the amount of water, the more watered-down the greenness of the chlorophyll becomes.
Brown and Rotten Orchid Roots
Overwatering can eventually cause your orchid’s roots to become waterlogged and rotten. This happens gradually, so you can catch overwatering before it gets to this point.
The problem starts when the roots have to sit in water for a long time. This can happen either when the orchid is placed in a pot that doesn’t drain, in potting mix that doesn’t dry out quickly enough, or if you keep watering the plant even when it doesn’t need more water. The roots absorb too much water, which damages them on a cellular level, and the water softens the root overall.
At the same time, bacteria is reproducing in the water. Bacteria need two things to create copies of themselves: water and food. They get their food at first from the potting mix, which contains all sorts of minerals and nutrients (this doesn’t apply to inorganic mixes like perlite or styrofoam). But they can also feed on the roots themselves, and break them down. That’s what rot is: it’s when bacteria start to eat away at something.
Unfortunately, this issue will only progress unless you fix the overwatering problem. Even if you do, it will probably still keep getting worse. You have to trim away any rotten parts—as rotten roots can’t be revived—and replace the potting mix the orchid was sitting in.
All of that being said, there are very obvious signs that an orchid root is rotten. The first is that it turns brown. That doesn’t mean a light brown color, almost like a pale yellow. Rather, it means a deep brown-black color. Stuff generally turns brown and black when it goes rotten. Another symptom is that it will start to smell. When you take your orchid from its pot, you will notice a very typical, very organic rotten smell that’s instantly recognizable.
Decomposing Potting Mix
Organic orchid potting mix can rot, too. When it does, it breaks down into more of a soft, mulchy stuff. This holds onto water much better than regular potting mix, which is bad. You don’t want that. It also provides the perfect breeding ground for bacteria, which will reproduce and go on to attack the roots as well as the mix.
This decomposition typically starts from the center of the pot, where you can’t see it happening. That’s because the core of the pot dries out slower. You may therefore only spot this if you repot your orchid. The mix will be damp, wet and clumped together, and may fall out as one mass rather than in pieces like regular mix.
If the mix is decomposing, you should replace it with fresh. You can’t reverse the decomposition process, and damp, claggy mix isn’t suitable for your plant. It typically takes about two years before orchid potting mix starts breaking down, so I repot my orchids roughly that often whether I notice symptoms of overwatering or not.
Shrivelled Yellow Orchid Leaves (Overwatered Orchid Leaves)
If you allow the roots to remain rotten, your orchid won’t be able to take in water for obvious reasons.
This is often the death knell of an orchid. That’s because the orchid looks like it has the effects of underwatering. In a sense, it does: it can’t get any water through its rotten roots, so its leaves start to shrivel up. This prompts the owner to start watering it even more, even though the problem in the first place was that the roots were rotten. This in turn makes the rot worse, because if the roots didn’t have a chance to dry out before, they definitely don’t now. With the extra water, more of the roots will rot until the orchid is left with none. The rot may then spread into the main body of the orchid.
If you’ve never seen shrivelled orchid leaves before, they look as you imagine them. They go leathery and wrinkled, and turn floppy so that they hang down over the side of the pot.
These limp leaves may also start to turn yellow. This is a function of them getting less water, too, just like turning leathery is. This time, the yellow color is caused by the leaf dying. It will first go a pale yellow before turning a deeper brown or reddish color and falling off. This looks much the same as when a leaf dies of old age, but in this case, it happens to all the leaves—not just those near the base of the orchid’s body.
An overwatered orchid will eventually die. Its roots will rot away, and its leaves will shrivel up and drop off one by one. If you don’t change the way you care for your orchid, and the problem is overwatering, then this is an inevitable outcome.
How Do I Fix an Overwatered Orchid?
It is possible to fix overwatering in orchids if it’s spotted soon enough. That applies even if some of your orchid’s roots have started to rot. But if you do nothing, and only carry on as you did before, then your orchid will die.
Step 1: How to Check for Symptoms of Overwatering
The first thing you need to do is check for the signs of overwatering.
Take your orchid from its outer pot, ideally on the day that you were due to water it. Look through the plastic inner pot to see if the roots are discolored, soft, brown or clearly dead. Examine the potting mix as well: is it still wet, or at least damp, and is there a lot of condensation no the inner wall of the pot? If these criteria are met, then you may have been overwatering your orchid. If these symptoms are present alongside withered leaves, then the issue is probably overwatering/root rot.
If there does seem to be a problem, I would recommend taking the orchid entirely from its pot to get a good look at its root system. Doing so will allow you to see the roots that aren’t visible from the outside of the inner pot. This is where the effects are at their worst, because water evaporates slowest from the core of the pot than from the top and sides. So even if the roots aren’t yellow/brown from the outside of the pot, those at the core of the pot may be; ditto for the decomposing potting mix.
To take your orchid from its pot, get a large bowl and hold your orchid over it. Tilt it at about 90 degrees, and hold loosely around the orchid’s main body. Gently massage the plastic inner pot, and some of the topmost potting mix will come free. Pull consistently but gently at the orchid’s main body, moving it away from the pot. If there are roots that poke through holes in the bottom of the pot, you can guide them through; they’re surprisingly resilient. But if they can’t go through, you have to cut them away. When you finally have the orchid free, get rid of the last of the potting mix and take a good look at all of the orchid’s roots to check for symptoms.
If your orchid isn’t overwatered, but is sick for some other reason, fix the problem. If it’s overwatered, carry on with the steps below.
Step 2: Repot Your Orchid
You should fully repot your orchid, whether or not it’s in a potting mix that’s suitable for it. This is best for the long-term health of your orchid.
To fully go through with the first step, you need to take your orchid from its pot anyway, completely removing it from its potting mix. Since it has experienced overwatering, it’s likely to have one or two rotten roots, which should be cut away. Take a sterile cutting tool and trim away anything that’s rotten, taking care to cut a little bit into the healthy root just above the rot. You should then let the orchid dry out for a day or two.
Once its roots seem dry, you can repot it in new mix. Pick sphagnum moss or coconut bark, as these two mixes are good at holding onto some water, but not too much. Follow basic repotting guidelines:
- Line the bottom of the pot with potting mix.
- Hold the orchid’s root ball in your hand, and try to place some mix in between the roots. Hold the mix and roots in place.
- Lower the root ball and mix into your orchid’s pot gently. You can leave some roots outside of the pot, so long as the orchid seems stable. It won’t be fully stable until you pot it.
- Pour some mix into the pot. Poke it through with your fingers, but don’t pack it down tightly. Fill the pot until the mix is nearly at the top.
One mistake I made once is to dry out the mix before using it. It’s normal to bake potting mix before using it, as this kills any pathogens like fungi. After it’s baked, you soak it for a while, because otherwise it stops being able to hold onto much moisture. I figured that an orchid with overwatering would benefit from a drier mix, at least for the time being, so I repotted it without soaking the mix; but over the next couple of weeks, it started to shrivel and dry out. The problem wasn’t rotten roots, it was that the mix held onto next-to-no water.
Step 3: How Often Should You Water an Orchid?
I water my orchids once per week. I find that that’s perfectly frequent. By the day before I water them, their pots are almost entirely dry. The topmost layer of potting mix is completely dry to the touch, and there are one or two droplets of moisture inside the pot further down. But by this point, the roots in the pot have turned from green (recently watered) back to their light gray/white-ish color. This tells me that they’re ready for more water.
You may find that it takes a longer or shorter time for your orchid to need water again. That’s perfectly normal, because the conditions you keep your orchid in are probably slightly different to the ones I keep mine in. I live in a colder place without much sunshine, but I can get a good through draft, so there’s lots of air flow. You might live somewhere that’s sunny, but you can’t get the air moving; or you have an AC that dries out the room. It doesn’t matter, so long as your orchid’s potting mix gets dry between waterings for a day or so.
If you’re not sure how often you should water your orchid, you could always try an experiment. Take one of your orchids and water it once a week. Take another and water it once every ten days. See which one does better. That’s what I love about keeping orchids: you can perform little experiments and improve how well you care for them even without expert advice. That’s how I learned much of what I know, anyway.