The Calathea plant (prayer plant) is a gardeners’ favorite primarily because it requires almost no maintenance.
Their unique green foliage always brings a rare sense of nature to your living room.
However, a major pain point for calathea enthusiasts is the curling of the plant’s leaves.
What causes the leaf curling, and how can you fix that? Let’s dive in.
Why Calathea Leaves Curl?
If you’ve been growing calathea for a while now, you must have noticed the leaves curl often, and this might have gotten you lost on what the problem could be.
Calathea plants curl their leaves due to dehydration brought about by dry air in their growing environment.
Your next action step would be to mist or water the plant immediately, but that is not where you should start.
You want to dig deeper into other potential causes of curling before deciding on the best remedy.
Causes of Calathea Leaves Curling
We have determined that calathea leaves curl primarily because of dehydration. But there could be other potential causes.
Some of them include:
- Too Much Lighting
- High temperatures
- Low humidity
- Impure water
- Pest Infestation
We shall be looking at each of the above factors in great detail and the corresponding solutions.
1. Too Much Lighting
Calathea is a tropical plant that thrives well under low lighting conditions found in its natural habitat. You’ll typically find them growing under the shade of tropical forests.
You want to mirror the same growing conditions indoors. Too much lighting for your calathea leaves is harmful since it will cause them to droop and curl.
Check the position of your calathea houseplant and determine whether it is receiving too much sunlight. A healthy Calathea will follow the direction of light to get more of it.
On the contrary, an unhealthy Calathea will curl to protect itself from the excessive sunlight. Calathea thrives best in bright indirect or filtered light.
2. High Temperatures
Your calathea leaves curling could also be a result of high ambient temperatures. High temperatures mean high evaporation rates causing your plant to lose a lot of moisture.
What is left are stressed drooping leaves. If your Calathea plant is located in the corner of your living room, move the plant to a cooler location.
We recommend growing your Calathea plants within a temperature range of 18-24 degrees Celcius. Monitor how your plant responds and adjusts your temperature accordingly within the given range.
Ideally, invest in a good thermometer and a thermostat. The gadget helps you maintain temperatures conducive to the healthy growth of your indoor plants.
3. Low Humidity
Another causal factor for curling in your Calathea is low humidity level or exposure to a less humid environment.
As earlier highlighted, Calathea is a tropical plant that thrives best under average temperatures, a misty atmosphere, and conducive precipitation. You will notice leaves curling in the plant under continuous dry air.
Luckily, there are several ways to adjust your indoor humidity levels.
Use a hygrometer to measure the levels of humidity around your Calathea plant. A humidity level of 50% or below isn’t conducive to its healthy growth. You should aim for 60% and above.
To adjust the humidity level upwards, you could use a spray bottle to mist your plant.
Another alternative would be using a pebble tray. Find a tray and collect pebbles from a nearby water body or buy them online.
Spread the pebbles over the tray and pour water so that they are not entirely submerged. Sit your Calathea pot on top of the pebble tray.
When the water in the pebble tray evaporates, it leads to moisture formation around the plant keeping its environment humid.
Another way to fix low humidity levels in your room would be to invest in a humidifier. It’s suitable for adding humidity to your house during the winter months.
You may also want to check what rooms in your house have higher humidity levels than others and transfer your plants there.
A well-balanced fertilizer is suitable for your Calathea, but be mindful of the dose. Overfertilization leads to dehydration ultimately. This is easily noticed by a build-up of crust on the soil surface.
When the root environment becomes oversaturated with chemical elements, they lose more water. Also, the roots may pull water from the top portion of the plant.
The leaves then begin exhibiting symptoms of dehydration by wilting and curling. The lower leaves will appear greenish-yellow and dry.
Too much fertilizer also results in curled and dry leaf edges.
To fix the problem of overfertilization for Calathea, you may want to transfer the plant to another balanced or natural growing medium.
First, uproot the plant from the salty medium and wash off the roots. Afterward, move it to a balanced medium, maintaining an appropriate fertilizer regime.
Avoid fertilizing your plants when you’re unsure about the measurements since this always leads to overfertilization. We recommend an all-purpose fertilizer in the ratio of 10-10-10 (Nitrogen/ Phosphorus/ Potassium).
You will know your Calathea plants are underwatered by checking the potting soil with a soil moisture meter or inserting your finger two-inch deep into it.
If the soil feels crusty, that’s a clear sign of underwatering. Look out for other symptoms which are likely to be similar to those of a less humid environment.
The water-deprived plant curls to prevent further moisture loss. The lower leaves may turn yellowish with spots.
You should keep the potting soil for calathea moist except during the winter months.
Another pitfall you want to avoid for your calathea plants is overwatering, which leads to root rot.
The condition interferes with nutrient and water absorption of your calathea roots.
The ripple effect is that Calathea leaves cannot receive enough water from the roots leading to brown tips and leaf curling. An early sign of root rot infection is a strong odor from the soil.
To avoid overwatering problems in the future, constantly water your plant only when the topsoil is dry. You also want to ensure your plant pot has enough holes to drain off excess water.
If the water takes longer to dry, you may consider transferring your calathea to another potting mixture containing a mix of coarse materials to aid in aeration and drainage.
7. Hard Water
If you’ve been watering your plants using hard water, that is another recipe for disaster. Hard water is riddled with calcium carbonate and fluorides.
Depending on your water source or supply, an excessive build-up of these salts and compounds inhibits essential physiological processes in the plant.
Fluorides inhibit photosynthesis which leads to tissue damage, while calcium carbonates cause water to flow back from the roots to the soil.
Against such a backdrop, calathea plants will be deprived of water and respond by curling their leaves to prevent further moisture loss.
If you spot the leaves turning dry, brittle, with brown tips, this is a clear indicator of fluoride poisoning. The leaves and stems will also be coated with white chalky residue.
Solve the hard water problem by repotting your calathea in a fresh soil mix. You should also water your plants with only distilled or filtered water.
8. Pest Infestation
Pest infestation is yet another reason why your plant leaves could be curling.
Pests such as spider mites have an affinity for Calathea. They usually target the plant tissue and sap, causing disfigurement and curling of leaves.
Use neem oil or other insecticides to get rid of them. Wipe off the leaves regularly using a mixture of mild soap and water.
That’s it! You now know why your calathea leaves curl. They are sensitive to conditions that don’t rhyme well with their natural habitat.
The curling behavior is a defensive mechanism to reduce surface area and prevent more moisture loss via evaporation.
You can quickly identify the cause using this handy troubleshooting guide and restore the plant to its peak health.