11 Common Problems With Calathea Plants
Does your calathea plant look a bit unwell? There are actually a few common issues that can impact these popular houseplants, depending on how they are grown. In this article, gardening expert and houseplant enthusiast Madison Moulton walks through the most common calathea problems, and how to fix them!
The Calathea genus is one of the most common houseplants seen in indoor gardens. Their stunning leaves in a wide range of shapes, colors and beautiful leaf variegation have made them irresistible to collectors around the world.
Unfortunately, they are not without their issues. Calatheas can be quite fussy, especially if you have a rarer variety that is difficult to keep happy.
If you’ve encountered any problems with your Calathea, causing it to look a bit sad compared to when you first bought it, go through this list to find the cause and apply the relevant fix. Let’s dig in and take a deeper look at the most common problems you may run into with this picky houseplant.
Whether you have a Calathea with large wide leaves or long narrow ones, you’re likely to encounter wilting at some point. This common problem has a number of reasons, and most of them are luckily easy to fix.
As with most leafy plants, the most likely cause is underwatering. Plant cells are mostly made up of water, filling up space and allowing them to maintain their structure. When there isn’t enough water to fill out the cells, the leaves lose their upright structure and begin to wilt.
Watering the soil deeply or watering from the bottom until the soil is completely saturated should resolve the problem within a few hours.
Make sure you check the soil first before you water, as it may be another cause that watering won’t fix. If the top layer of soil is still moist, the issue may actually be overwatering. Excess moisture in the soil causes the leaves and stems to become mushy due to rot, resulting in the same wilting as with underwatering.
Leave the soil to dry out completely or, if the problem is severe, repot into fresh soil to save the rotting roots.
Low humidity, lack of light or transplant shock after repotting are other potential causes. Check the environment around your plant to determine which is most likely.
Curling leaves may look more severe than wilting leaves, but the causes are largely the same. This is a process Calatheas use to protect themselves when conditions are potentially damaging to them, conserving moisture and reducing exposure until the environment improves.
The main culprit, again, is underwatering. Severely dehydrated plants will start by wilting, eventually curling inwards to retain as much moisture in the leaves as possible. Another moisture issue – lack of humidity – may also be the cause.
Test the humidity around your plant. If it is well below 40%, improve conditions using a humidifier. For humidity above 40%, water the plant and wait for the leaves to return to normal.
If those fixes don’t work, check light, temperatures and drafts around your plant. High light exposure can lead to curling leaves to limit damage. High temperatures can also result in curling to prevent loss of moisture in the leaves, and cold drafts can cause the leaves to shrivel. Keep temperatures moderate and move the plant out of the way of drafts to resolve the problem.
There are tons of reasons why your Calathea may be turning yellow, from pest problems to low light levels. However, the most common issue is overwatering.
Calatheas do like moist soil, but not excessively moist soil. Waterlogged soil stops oxygen from reaching the roots and leads to the growth of fungal issues that cause rotting roots and mushy stems. Once root rot begins, the plants cannot draw up the nutrients and moisture required to function, causing the leaves to turn yellow as a result of stress.
Allow the soil to dry out slightly and check the performance of your plant. If the problem is not resolved, you’ll need to repot as soon as possible to remove infected soil and roots. Trim away problematic areas and plant in new soil and a new pot to recover.
Other issues to look out for include:
- Low Humidity
- Pest Issues
- Fungal Infection
- Transplant Shock
- Sudden Changes In Environment
Finally, some yellowing on the lower parts of the plant is nothing to worry about. Older leaves will eventually turn yellow, then brown, and fall off the plant. As long as it’s only a couple of lower leaves and new ones continue to emerge, you can ignore the issue.
The colorful and patterned leaves of Calathea plants can be quite sensitive, depending on your chosen variety. If conditions are not quite right, you may encounter a common issue among Calathea growers – leaves turning brown at the edges.
The first issue to look out for is a moisture problem. Both underwatering and lack of humidity can cause the edges of the leaves to dry up and turn brown. This usually begins at the tips and slowly spreads to the rest of the leaf if the issue is not fixed.
If you are watering regularly, the other concern could be the quality of the water you are using. Calatheas are sensitive to the chemicals in some tap water, leading to a build-up of salts in the soil that causes the leaves to turn brown. Salt build-up from overfertilizing can lead to the same issue.
In these cases, flush the soil with filtered water until it runs clear. Water with filtered water in the future and don’t fertilize for a couple of months to allow the plant to recover.
Yellow & Brown Spots
Discoloration isn’t always concentrated in one area or across the whole leaf. Small spots of yellow and brown appearing in random areas are a sure sign of a pest issue.
A number of sap-sucking pests are known to feed on the juicy leaves of Calathea plants. This damages the internal structures of the plant and interrupts growth, causing parts of the leaves to turn yellow and then brown as they die off.
The first response to a pest problem should always be quarantined. Move the plant to an isolated spot away from any other houseplants to prevent spread. Then, treat with insecticidal soap or horticultural oil to remove the bugs, using repeat applications at recommended intervals until all the pests have been removed.
Calathea leaves generally stand strong and upright, proudly displaying their stunning colors. Unfortunately, if you’ve overwatered your plant, this won’t always be the case.
As mentioned before, Calatheas are very sensitive to overwatering. They hate sitting in soggy soil which quickly leads to root rot underneath the soil. This problem can also spread above the soil line, causing the stems to rot at the base. The lack of structure will also cause the stems to fall over and the leaves to wilt.
Root rot is a serious issue that requires immediate attention. Once the stems have become soft, a large number of roots are likely rotting below the soil too. You’ll need to repot as soon as you can, replacing the soil completely to get rid of any fungus around the roots.
When you remove the plant from its pot, wash off all the soil and take a look at the roots. Trim off any rotting areas back to healthy growth to stop potential spread in the new soil. Make sure you wash your shears with soap and water afterward too.
Repot into a new pot with plenty of drainage holes. Soil choice is also vital – make sure it is amended with coconut coir or peat moss and perlite to improve drainage and prevent rotting in future. Then, to stop yourself from overwatering again, make sure to test the soil every day with your finger, only watering when the top layer has dried out completely.
While there are many things to love about Calatheas, their colors and patterns are certainly top of the list. So it is understandably distressing when those colors begin to fade, looking dull and diminished compared to when you first bought the plant.
The main reason for problems with color in Calatheas is sunlight – specifically, too much of it. Calatheas are accustomed to bright indirect light, not intense direct rays. If they are placed in the path of direct sunlight during the hottest parts of the day, the leaves will likely become pale due to sun damage.
Other signs of high sunlight exposure include curling and brown patches on the leaves close to the light source. If you notice all these factors combined, make sure you move the plant out of the path of the direct sun straight away, or cover your window with a shear curtain to filter the sun’s rays.
Make sure the area you move the plant to doesn’t have too little light either. Low-light areas are not suitable for most Calathea species, leading to stunted growth and yellowing leaves. Aim for bright but indirect light for the best possible performance.
Bugs Around Soil
Creeping crawling bugs are generally not welcomed in our homes, but especially aren’t welcome in our houseplants. Unfortunately, they are not always easy to avoid. If your Calathea is in a low-light area where evaporation is low and soil remains moist, it is likely to attract one of the peskiest indoor pests – fungus gnats.
Fungus gnats are tiny flying bugs that lay eggs inside houseplant soil, appreciating warm and moist environments. They buzz around your plants (and eventually your own heads when the problem is severe), causing endless annoyance and damage to your houseplants too.
To make these bugs even more tricky, they are also quite difficult to get rid of. If you try to spray them with insecticidal soap or horticultural oil, they will simply fly off the leaves, coming back when all signs of danger have passed.
To rid your home of fungus gnat problems, you’ll need to try a couple of things. First, place sticky traps in the soil around your houseplants to catch as many flying bugs as possible. Also consider repotting your plants to get rid of any eggs or bugs hiding out in the soil. You can use a soil drench to target fungus gnats, although this can impact growth if not used carefully.
White Substance On Leaves
Another common pest to look out for is mealybug. These sap-sucking pests are small but easy to identify by the white substance they use to protect themselves while feeding on foliage. White fluffy powder around the leaves and stems – especially if it is currently moving – is a guaranteed sign of mealybug.
As with all pest problems, start by isolating the plant. Wash off any visible bugs, making sure you check the undersides of the leaves where they like to hide out. Then, apply insecticidal soap or horticultural oil to all the leaves as per the instructions on the packaging.
Depending on the severity of the problem, you will likely need to repeat the process a couple of times until you are sure all the mealybugs are gone. If not, they will quickly reproduce again and may even come back stronger than before. Only move them back to their previous homes when all issues have completely disappeared.
Bumps On Stems
Although less likely on Calatheas, you also need to keep an eye out for scale insects. These tiny crawling bugs are usually found on the stems. They dig their teeth in and settle down to feed on any water and nutrients that come through the stems, depriving the leaves.
Scale can be tricky to spot as they are so easily camouflaged. Continually check the stems for tiny bumps in irregular patterns. You will also notice wilting and a lack of new growth in affected areas.
Apply the same steps in irradicating scale as with mealybug. Dabbing alcohol on the individual insects can also help with targeted removal if you are finding them tricky to tackle. Keep your Calathea in the right environment and give them the right care to limit your risk of scale problems.
Webbing Between Leaves and Stems
Small webs between leaves and stems indicate one common pest problem – spider mites. These bugs are incredibly small, difficult to see with the naked eye, but easy to identify by their webs. Look in areas with stems and leaves close by where there is little airflow and you may notice them gathering there.
Again, isolate the plant and treat as many times as required to remove the problem. Unfortunately, there is no way to keep spider mites from infesting your plants completely, but there are things you can do to limit your risk, such as removing damaged leaves and keeping humidity high around your plant.
Calatheas can be fussy plants, depending on the species you have. However, any problems you encounter are usually not impossible to solve. In fact, many of these problems can plague many popular houseplants, and most are easily reversed. Use this list to determine which problem is most likely and change the conditions until your Calathea is strong and happy again.