Many people have a love-hate relationship with Calathea. Also known as prayer plants, they have a reputation for being fussy and hard to care for, which is why the genus is not usually recommended for beginners. However, once you figure out what works for your plants, they can be an absolute delight to have in your home.
Keep reading to find out some of the common Calathea problems, so you can troubleshoot whatever might be affecting your plant.
2022 update: Lots of species that were previously in the genus Calathea, like the popular rattlesnake Calathea (Calathea lancifolia), have been moved to the genus Goeppertia. The aforementioned plant is now Goeppertia insignis, for example.
Luckily, this troubleshooting guide applies pretty well to all species in the family Marantaceae. This includes Calathea, but also Goeppertia, Ctenanthe and even Maranta.
Before we start…
All in all, the most common cause for issues with a Calathea is excess moisture. If reducing your waterings doesn’t help halt the process, you’ll unfortunately have to uproot your plant. Check the roots and lower stems: do they appear black/brown and mushy? Are they smelly?
If the answer is yes, that indicates rot due to bacterial or fungal infection. You will need to remove all afflicted roots and repot into a new, well-draining mixture.
Always use a planter with a drainage hole and give the plant plenty of bright indirect light. Keep the soil lightly moist, but never let a Calathea sit in a soggy pot.
If the stems are rotting, there unfortunately really isn’t much you can do.
Tip: To prevent issues like poor drainage and too little light, you have to know what your Calathea needs. You can find out everything you need to know in the full guide to Calathea care.
Calathea yellow leaves
Problem: Foliage yellowing at an alarming rate
Causes: Watering issues, sunburn, shock, nutrient imbalance
Unfortunately, this is a very generic symptom. It can mean many different things:
- Overwatering. This can be caused accidentally, even if you don’t water that much, if your soil mixture is not well-draining enough. It can also happen if your plant doesn’t get enough light to process the water you’re giving.
- Natural shedding of lower leaves. As a plant grows, it will reabsorb nutrients from lower leaves, turning them yellow and then crispy and brown before they drop. This is normal, so if it’s only lower leaves and they’re not yellowing at an alarming rate, you’re likely fine.
- Over-exposure to sun. Refer also to the paragraph on leaf pattern loss. Suddenly being moved to a sunny place or simply receiving too much direct sun will cause leaves to yellow and crisp up pretty good.
- Plant is cranky. Calatheas seem quite sensitive to changes like being moved (like when you buy it), repotting and division. If you just did any of those things, give your plant a few weeks to come around.
- Underwatering. Consistent underwatering can cause yellow leaves on a Calathea. However, you’d also expect to see some other symptoms, like leaf droop and leaf curl, before they start discoloring.
- Over- or underfeeding. You might have used too much fertilizer, which can be corrected by flushing the soil with distilled water. If you’ve never really fertilized, a bit of houseplant food every month or so during the growing season might help.
Calathea leaves curling
Problem: Foliage curling inwards or outwards
Causes: Thirst, soil compaction, watering issues
Calathea leaves curling and wilting can be an indication that you’re not giving your plants enough water. What makes this even more frustrating is that they can also indicate that you’re actually overwatering instead! It might also just be the plant being cranky due to being moved or repotted.
So how do you find out which one it is? It’s a bit of a process of elimination.
- If the soil is dry, give the plant a drink and see if the leaves uncurl in the next few hours. If they do, adjust your watering schedule. You’ve been underwatering. This especially applies if the leaves are also turning crispy.
- If the soil is moist but the leaves are wilting, aerate the soil by poking into it using a chopstick. This ensures water can reach the roots.
- Leaves still wilting after that even though the soil is not dry? There’s a chance you overdid it previously and the roots are rotting, so you might have to uproot the plant to check.
Calathea brown tips
Problem: Leaf tips are browning
Causes: Watering issues, mineral build-up, sunburn
As it was mentioned earlier, browning leaf edges on Calatheas are often a sign of low humidity. See the last paragraph for more on that.
It can also potentially indicate the following:
- Underwatering. Consistent underwatering may eventually cause your Calathea to develop brown leaf tips. As mentioned in the previous paragraph, if the soil is moist but the plant still seems thirsty, be sure to aerate the soil.
- Overwatering. Yep, there it is again: almost all Calathea symptoms can have something to do with excess moisture.
- Mineral build-up in the soil. Calatheas can be sensitive to the salts and minerals in tap water. As with all your houseplants, you should thoroughly flush your Calathea’s soil every few months. This can be done with distilled water, which will take the excess minerals with it while it flows out of the planter.
- Exposure to too much light. Sudden exposure to might higher light conditions, or putting your Calathea in full sun, can cause the leaves to burn. Always acclimate the plant slowly if you’re changing light conditions.
Damaged leaves can unfortunately not be fixed, though be sure to go over the care you’re providing and correct any issues.
New foliage should be healthy and eventually replace the old, brown-tipped leaves.
Calathea leaf pattern loss
Problem: Calathea leaves fading
Causes: Lighting issues, nutrient deficiency
Because Calatheas are loved for their gorgeous leaves, it’s heartbreaking if the patterns start to fade. The following issues are most strongly associated with this symptom:
- Too much light. If your Calathea is getting too much light, the leaves will appear faded, translucent even. The chances of this happening indoors are not that high, but if it has, just move the plant a few feet away from the window.
- Too little light. If the leaves on your plant appear faded and it’s in a low light spot, that might be it. Unfortunately you have to accept that all plants need light and they can’t be in a dark spot in the home. Slowly acclimate your Calathea to a higher light location.
- Underfertilization. If you’ve never really fertilized and the plant has been in the same soil for a while, it might be struggling. Use some diluted general houseplant fertilizer about once a month during the growing season.
Mushy stems on Calathea
Problem: Calathea “melting”
Causes: Root rot progressed to stem rot
If your plants have mushy stems, it’s a sure sign that you’re overwatering and that your plants are suffering from rot. If you dig into the soil, you may find that the roots are also mushy and rotting away.
If it’s just the roots, remove all afflicted parts, repot into fresh soil and say a little prayer. If it’s the stems too, then unfortunately your Calathea can probably not be saved.
Problem: Calathea wilting
Causes: Watering issues, cold
You may notice that the leaves of your Calathea plants droop more during the day. This is completely normal since the leaves fold up during the night, then let loose during the day!
If the drooping is significant, there might be something else going on. The causes are quite similar to those of curling Calathea leaves.
- Underwatering. The most common cause, so check the soil. If it’s dry, then you’ll have to indeed adjust your watering schedule. If the soil is moist then aerate it in case the water is not reaching the roots.
- Overwatering. If the soil is quite wet, you’ll have to either water less or move the plant to a higher light location.
- Drafts and low temperatures. These guys are tropicals and they like things nice and toasty! Room temperature is perfect for them.
Problem: Bug invasion!
Causes: Spider mites, thrips, mealybugs & more
If your Calathea’s leaves are showing speckled discoloration or crisping up, drying and browning, you might have to whip out the magnifying glass. There’s a chance the plant is infested by unwelcome visitors!
Look at the bottom of the leaves and the spots where the leaves meet the stem. Also keep an eye out for little flies. A few of the common culprits are:
- Spider mites. They love Calatheas and are frequent visitors that can get out of hand. They like dry air, meaning infestations generally happen during winter. Up the humidity and give your plant frequent leaf showers. That should usually do the trick.
- Fungus gnats. These pop up when the soil is consistently moist. Their larvae munch on your plant’s roots. The first step is letting the soil dry out a bit more. If that doesn’t work, try mixing one part 3% hydrogen peroxide with four parts water and apply this to the soil.
- Scale. If your Calathea’s leaves have a sticky substance on them, this is a likely one. Scale excretes honeydew in order to feed ant colonies that protect them. Scale looks like brown or greyish bumps on the plant. You can try an insecticide or removing manually by attacking the scale with a cotton bud dipped in rubbing alcohol.
- Mealybugs. UGH. The worst of all in my opinion! As described in the guide to mealybugs, these cottony looking small bugs like hiding in leaf and stem crevices and sucking the life out of your Calathea. Try neem oil to remove them or move straight to the insecticide; they can be in the soil as well so it’s really difficult to remove these guys.
Increasing humidity for your Calathea
If you don’t have one yet, a humidity meter is incredibly helpful if you’re a houseplant enthusiast. If the humidity is under 50-60%, that’s the first thing to fix in your journey to figure out what’s going on with your Calathea.
Increase the humidity by placing the plant in a more humid room like the bathroom, placing multiple houseplants together or, most effectively, running a humidifier.
Tip: Seriously, if the humidity in your home is low, run a humidifier. Low humidity can affect you as well as your plants!