If your Calathea is unhappy, it will curl its leaves subtly or completely fold over into a loop. This is often a warning sign before the problem worsens and may develop yellow or brown leaves.
Your Calathea’s leaves are most likely curling because it is dehydrated, either due to being underwatered, receiving too much light, or insufficient humidity levels. In this case, it is curling its leaves to protect itself and slow the process of transpiration. Other reasons your Calathea might be curling its leaves are due to energy depletion caused by pests or shock.
If you identify the problem and quickly take steps to fix the reason for the leaf curl, your Calathea should make a full recovery without any permanent damage.
1. Your Calathea May Be Underwatered
The most likely reason your Calathea has curled leaves is that it is underwatered.
Calatheas have very delicate foliage, so they do not retain as much water as a plant with more succulent leaves would.
In addition, most tropical houseplants undergo a process known as transpiration, where water can evaporate from the leaves. This transpiration contributes to tropical humidity in their natural environment but can cause problems when Calatheas experience drier conditions.
If your Calathea is dried, the leaves will curl to trap the transpiration and retain as much moisture as possible. This is often the first sign that your Calathea is thirsty before you notice yellow or brown leaves. The leaf curl will start subtly and eventually curl upwards into a loop.
How to Fix Leaf Curl Due to Underwatering
To fix the curl, give your Calathea a thorough watering.
If the soil is completely dried, water it once more after a few minutes since most of the water drains right through the soil.
You can also try bottom watering your Calathea. To do this, fill a large bowl with room temperature water and place your Calathea’s pot into that bowl. The soil will gradually absorb the water as needed through the drainage holes. Once the soil at the top of your pot is moist, then you can remove your pot from the bowl of water.
If you find that you frequently forget to water your Calathea on time, here are a few tips:
- Purchase a moisture meter, so you can have a better understanding of when your Calathea’s soil is wet, moist, or dry.
- If your Calathea is in a very chunky soil mix, add some moisture-retaining substrate to the soil, like coco coir or potting soil.
- If your Calathea is in a terracotta or clay pot, consider repotting it into a plastic pot or a ceramic pot that retains moisture more effectively than clay. You may also want to consider trying a self-watering pot, which reduces the frequency you need to water your Calathea.
- Make sure that your Calathea does not need a new pot. If your Calathea has overgrown its pot (roots are poking out of the drainage holes or poking out of the top of the pot), it may crowd out the soil and dry out more frequently.
2. Too Much Light
Along similar lines of insufficient water, your Calathea may be curling its leaves to protect itself from excessive light.
In their natural habitat, Calathea grows along the jungle floor in relatively low light conditions, receiving dappled sunlight from the forest canopy.
Most Calathea varieties have a dark aubergine backing to their leaves. This helps them to channel any light possible toward the green portions of their leaves, which assist with photosynthesis.
If your Calatheas leaves have curled upwards under bright light conditions, they protect the green parts of their leaves from excessive light.
This curling also prevents them from drying out too quickly. If left too long, the leaves may start to fade or even burn from excessive sunlight.
Calatheas prefer 400 Foot Candles of light but can tolerate light levels as low as 200 Foot Candles for minimum growth. If you aren’t sure what the light levels in your space are, consider purchasing a light meter!
How to Fix Curling Leaves From Too Much Light
To fix the curling leaves, move your Calathea to lower light levels.
Keep your Calathea in a location where it doesn’t receive direct light, if possible. While some Calathea varieties can tolerate an hour or two of direct sunlight, morning sunlight is preferred as it is much gentler.
If your options are limited and you only have windows with strong light, consider moving your Calathea further from your window or adding a sheer curtain for the light to filter through.
3. Your Calathea Could Be Overwatered
While less common, your Calathea may also curl its leaves due to overwatering.
Often there is a lot of overlap in the symptoms of overwatering and underwatering because the plant is undergoing a similar experience.
For example, if the roots sit in saturated soil for too long, they start to rot and will no longer serve their intended function of delivering water to the rest of the plant. This is why you may see similar curling in an overwatered Calathea as you would a Calathea that is underwatered.
If your Calathea’s leaves are curling, checking the soil will help you differentiate whether the problem is overwatering or underwatering.
How To Fix An Overwatered Calathea
If your Calathea has been overwatered, the best thing you can do is remove the wet soil it is sitting in for fresh soil. If the root rot is severe (dark, mushy, odorous roots), you will want to trim them away.
If the root rot comprises the majority of the roots in your Calathea, a great way to fix this is to place your Calatheas roots in distilled water. This will help them grow new, stronger roots much faster.
You will notice the leaf curling begin to reverse after a few days as the leaves will become hydrated again. Once more roots have grown, you can repot your Calathea back into the soil.
4. Not Enough Humidity
If you notice minor, subtle curling in the leaves where the edges are tucking slightly under the leaf, a lack of humidity could be the issue.
Having humidity levels at a minimum of over 50% and ideally above 60% are crucial to growing a happy and healthy Calathea.
Over time, these curling edges may eventually turn brown.
Once again, this is related to transpiration. Your Calathea is attempting to reduce the surface area of its leaves to prevent losing moisture too quickly.
Fixing Leaf Curl Due to Low Humidity Levels
The most effective way to increase humidity for your Calathea is to add a humidifier.
However, you can also move your Calathea to a more humid location like a kitchen, bathroom, or small greenhouse.
If your Calathea is on the smaller side, you can also keep it under a cloche, trapping that transpiration under the glass.
There are other small hacks to increase humidity in your space that you can try, such as using pebble trays, misting, or grouping tropical houseplants closely together. Still, you likely won’t achieve the same results as incorporating a humidifier into your Calathea care.
5. Pests Causing Leaf Curling
If your Calathea experiences a bad pest infestation, such as spider mites or thrips, you may find that its leaves are curling.
This is particularly common during a spider mite infestation. The dreaded webbing between the stems and dust-like mites under the leaves are two immediate signs to look for if your Calathea has curled leaves without any delinquent watering. Spider mites suck the fluids and nutrients out of the plant’s leaves, depleting the plant of energy.
If your Calathea is infested with pests, causing its leaves to curl, you will want to isolate and treat it immediately.
Use water to blast off the most visible pests, and use either insecticidal soap or neem oil to treat the leaves and stems. You may need to repeat this treatment several times until the pest problem is gone. In the meantime, give your Calathea plenty of time to recover.
Follow our guide here: How to Get Rid of Spider Mites on Your Calathea
6. Leaf Curling Due To Shock
Sometimes stress and shock can cause your Calathea to curl its leaves.
Most of the time, leaf curl due to shock is related to extreme temperatures. Calatheas prefer temperatures between 60°F and 85°F (15°C to 30°C). Therefore, you may notice their leaves curl if they experience an intense temperature drop or increase.
Some normal household activities that can cause your Calathea’s leaves to curl from temperature extremes include:
- Open windows during temperature drops
- Lack of airflow during heatwaves
- Keeping your Calathea close to a vent or an air conditioner
- Accidentally leaving your Calathea in a car on a hot or cold day.
- Shipping Calatheas during heat waves or deep freezes
- Keeping your Calathea too close to a refrigerator or freezer door
- Watering your Calathea with stark cold water
Your Calathea could also experience shock from a physical injury like being accidentally knocked over or nibbled by a pet.
Occasionally, you may even notice some leaf curling after repotting.
Recovery from Leaves Curling
In most cases, you will notice that your Calathea’s leaves will begin to uncurl after fixing the problem.
Depending on the cause, this could take anywhere from a few hours to a couple of weeks. The severity of the problem combined with how long the problem persisted will be a factor in the length of your Calathea’s recovery time.
After an incident where your Calathea has had curled leaves, you may notice that a few leaves will turn yellow or die off. This does not necessarily mean that you did not fix the problem. It could just be your Calathea attempting to conserve its energy by removing a few leaves.
While your Calathea recovers, it’s best to refrain from any drastic environmental changes until your Calathea recovers.
Keep your Calathea in a safe place that is warm and humid, and keep the soil moist until it starts to grow healthy new leaves before you repot it.
Are Certain Types of Calatheas More Prone to Curling Leaves?
While all Calatheas will curl their leaves when they experience the above problems, some Calatheas are more prone to leaf curling than others.
For example, Calatheas with very delicate foliage, large rounded foliage, or velvety foliage experience curl much faster than others.
Here are some Calathea varieties that are a bit more prone to leaf curling:
Calathea Ornata: Their dark green foliage makes them more sensitive to brighter light conditions.
Calathea Medallion: These Calatheas have large, rounded foliage, meaning they have a larger surface area for transpiration and will quickly curl when dehydrated.
Calathea White Fusion: This variety needs additional humidity. With some of the most delicate foliage in the Calathea genus, they stress easily by delinquent watering or temperature changes. They tend to be more prone to pests than other Calatheas. This will cause leaf curl and browning on the leaf’s white sections.
Calathea Zebrina: This variety has thin foliage that is also quite soft to the touch, making it more prone to dehydration and attractive to pests.
Calathea Warscewiczii: Their magnificent velvety foliage tends to attract pests. Their leaves grow pretty large and will dehydrate quite quickly. They also have a more rapid transpiration rate due to their leaf size, so keeping the humidity levels high and the soil moist is essential.
How to Prevent Leaf Curling
Once the leaves stop curling, here is how to prevent it from happening in the future:
- Keep the soil moist but not too wet.
- Water your Calathea with room-temperature distilled water (or, even better, rainwater if you can source and collect it).
- Keep the humidity levels high and temperatures warm where you keep your Calathea.
- Give your Calathea medium light levels.
- Monitor your Calathea regularly for signs of pests. Even if you don’t find any visible pests, periodically spraying down your Calathea’s leaves will go a long way in preventing infestations.
- Keep your Calathea’s leaves clean and free of dust.
It’s also a good idea to prune dead leaves as you see them and clean the surface surrounding your Calathea for any spilled soil or loose foliage. This will reduce the likelihood that you will have a pest outbreak.
Once you identify why your Calathea’s leaves are curling, you should be able to fix the problem. Leaf curl is usually the first sign that your Calathea is unhappy. If you can quickly determine the reason for the curl and fix the problem, there shouldn’t be any long-term damage to the plant.