What Temperature Can Calathea Tolerate? (Ideal Temperature Range)

Calathea is a tropical plant grown because of its beautiful patterned leaves and their dramatic movements. Being tropical plants, they need moderately warm temperatures for thriving. This is the reason they are mostly grown indoors.

But What temperature can Calathea tolerate? Let’s find out.

In general, calathea can survive in temperatures as high as 90°F and as low as 60°F. The ideal temperature for Calathea ranges between 65°F-85°F. Exposing Calathea to excessively high or low temperatures will harm the plant, and thus you must keep them away from cold and hot drafts.

It can be a bit difficult when it comes to providing the ideal temperatures to the houseplants. However, by the time you finish reading this article, you will learn how to provide the ideal temperature to your Calathea.

We will also share information about whether you can keep your Calathea in an AC room or not. So, let’s start.

What is the ideal temperature for Calathea?

Calatheas originate from the tropical regions of South America. Being tropical plants, they will grow best under temperatures ranging between 65-85°F.

You should not expose them to temperatures higher than 90°F or lower than 55-60°F.

If anytime the temperature around Calathea rises too high or drops too low, the leaves will show you some symptoms, like the browning at the tips and edges or curly leaves. 

These are indications that you need to either amend its surrounding temperature or shift the plant to a location where it can receive the ideal temperature.

Remember, these houseplants will be able to tolerate the exact temperature we humans can bear. They require average room temperature for thriving.

Sometimes, we keep our houseplants in open balconies or near open windows. For Calatheas, open balconies are not ideal because harsh sun rays can damage their leaves. 

Though open windows in the north or east are ideal, you need to bring your Calathea some feet away from the window when cold winds blow outside. This will save them from cold drafts. It is better not to keep Calathea in open balconies.

Another thing you should consider to save your Calathea from drafts is not keeping the plant directly under ceiling fans. Direct air can affect the plant’s health.

Some growers keep their houseplants in the kitchen for high humidity. It is fine. But keeping the plant too close to ovens will give the plant heat stress. 

Instead of keeping the plant in the kitchen, you can try keeping your Calathea near the bathroom. This place will also give your Calathea the required humidity.

You can also try other things, like pebble trays, humidifiers, or plant grouping for humidity. 

Effects of low temperature in Calathea

Being tropical plants, Calatheas are very sensitive to cold drafts. The very witness of this sensitivity is seen when the winters arrive.

As Calatheas do not like low temperatures, they gradually slow down their growth and become dormant.

So, other than the winter season, whenever you find that your Calathea is showing stunted growth suddenly despite getting all other requirements, the reason may be cold drafts.

Other than stunted growth, Calathea will show signs like curly leaves or browning at their edges and tips. These, too, are an indication of low temperatures for your Calathea.

When the damage reaches inside your plant, the cells start getting damaged and lose their rigidity. 

Moreover, low temperatures tend to reduce the humidity for Calatheas, affecting the plant’s health. Being tropical plants, Calatheas will need high humidity to survive.

Sometimes, the temperature drops too low, and the roots start freezing.

When this happens, your Calathea is doomed. However, this happens mostly outdoors. If your region receives snowfall during the winters, you will have to take extra care of your Calathea.

How to fix the problem?

You can measure the temperature of the location where you have placed your Calathea.

• Try figuring the direction from which the plant is getting cold drafts. If it is too close to the window, bring it a few feet away from the window.
• If it is under the ceiling fan, keep them away so that the fan’s air cannot touch the plant.
• Some houses contain air conditioners. If your Calathea is placed in such a room, try moving into another room with no AC. Or else, keep it away from the AC so that the cold air doesn’t touch or affect Calathea’s health.
• Do not put your Calathea near any heating devices when you find that the plant is exposed to cold drafts. Bringing the plant near any heating device will only worsen the situation.
• Calathea needs time to adjust to the new environment. Sudden change can shock the plant. Try changing the plant’s location gradually. It will get adjusted to its new environment slowly.
• Water the plant less if exposed to low temperatures.

In the process of providing your Calathea warm temperature, do not make the mistake of exposing it to high heat or high temperatures. It will also harm the plants. 

How and why high temperatures harm your Calathea are what we will be discussing in the next point.

Effects of high temperatures in Calathea

Just because Calatheas thrive in warm temperatures doesn’t mean that you should expose and keep them under high temperatures.

By keeping them under the direct sun, you are in no way giving them warm temperatures. This will result in sunburn and scorched leaves.

Calathea leaves tend to close up during the night as if they are folding to pray. That is why they are called Prayer plants. 

If your Calathea receives too much light, it will not fold up. Moreover, direct sun will cause heat stress. 

Bad health due to excessive heat will make the Calathea leaves dry up and curl up, and they will even start shriveling and develop brown spots or patches indicating sunburn.

Exposing the Calatheas to high temperatures will result in fast drying of the soil. 

In that case, if you do not give your plant extra water, it will suffer from dehydration and lack of nutrients. This will eventually affect the plant’s overall health.

How to fix the problem?

If you have kept the plant under the direct sun with the thought of keeping it warm, please shift your plant to shade soon. 

Direct sun is in no way giving your Calathea warmth. In their original habitat, they are habituated to growing under the canopies with lots of filtered sun.

• Try providing bright indirect or filtered sunlight.
• You can also use artificial lights to give it adequate light.
• Remember that Calathea will also need 8 hours of darkness. This will allow closing up of Calathea leaves at night, which signifies that your Calathea is in good health.
• To cool down Calathea a little, you can water your plant more often, during spring or summer. 
• If you have kept your plant inside the kitchen, bring out your Calathea. This can cause heat stress. Do not take it inside for a warm temperature. Keep it outside the kitchen door. 
• Some people keep their plants in the kitchen to provide them with high humidity. If it is too hot for your Calathea, keep it in the bathroom instead. This location, too, will provide good humidity and save your plant from getting heat stress.
• If your house has heaters or radiators, keep your Calathea away from them.

How can you give your Calathea the ideal temperature?

The best way to give your Calathea their best temperature is not exposing them to excessively high or low temperatures and keeping them under moderate room temperature.

As I mentioned earlier, Calatheas require a temperature ranging between 65-85°F. They should neither be under temperatures below 50-60°F nor over 85 to 90°F.

Instead of measuring the room’s temperature, measure the temperature of the location or surrounding your Calathea.

• If you have placed your Calathea near an open window, you can use transparent curtains or window films to protect the plant from the direct sun rays. 
• You can place your Calathea near the North or East-facing window. It will give your plant ample and less intense light and save it from getting any sunburn.
• Keep your plant away from heaters, ovens, radiators, or air conditioners. Also, do not keep your plant under a direct fan.
• To maintain the ideal temperature for your plant, you can alter the plant’s watering schedule. If your plant receives high temperatures, you can water your Calathea more frequently to keep them cool. 
• During the winters, the plant goes dormant. So you should cut back the watering amount and frequency compared to summers.

You should also ensure that your Calathea doesn’t receive temperature fluctuations and maintain the ideal temperature. 

• Don’t relocate it suddenly. Do it gradually. 
• Don’t keep your plant in a place where the windows and doors are frequently closed and opened. This allows the drafts to enter and touch the plant, causing stress.

An average room temperature is the best temperature for Calatheas, just like the one suitable for humans.

Will Calathea survive in air-conditioned rooms?

As Calatheas belong to the tropical regions, they will enjoy warm weather for proper growth. In cold weather, they don’t grow much and become dormant. 

But, despite this fact, you can keep your Calathea in an air-conditioned room, and it will still grow well. For instance, Calathea Zebrina will survive in an air-conditioned room, provided they are getting all other requirements adequately.

But you have to ensure not to expose them to the direct air of Air Conditioners. Your plant should also receive bright filtered medium sunlight and high humidity.

You can reduce watering to some extent while keeping Calathea in an air-conditioned room. Just keep the soil moist or try misting to moist the soil. The plant should not remain dry.

For keeping Calatheas healthy in an air-conditioned room, you need to follow certain things:

Hydration: Remember to keep your Calathea hydrated. Do not overwater. 

The cold, dry air might dry up the soil quickly. This further causes difficulty in the absorption of water and nutrients from the soil. So keep your plant’s soil under check and water them adequately.

Watch for the right location: The direct cold air from the air conditioners or cold drafts can damage the cells and curl the leaves. 

So, while growing Calathea in an air-conditioned room, locate it in a spot away from the AC. Also, make sure they are getting good filtered sunlight.

Maintain the correct humidity: When you keep your Calathea in an AC room, it will dry out the soil quickly and reduce the humidity. 

Watering will only take care of hydration. However, misting might help in both hydration and humidity. But that is temporary. Within 20-30 minutes, the water will dry out.

To maintain the ideal humidity for your Calathea, you can fix a humidifier in the room. If you can’t get a humidifier, you can keep a pebble tray filled with water under your potted plant. It gives extra humidity to your plant. 

You can also group your plants. If you own many tropical plants, group them. The plants will create humidity. But along with grouping, take care of the space between the plants for good ventilation.

Protect your plant: You can protect your Calathea from the cold air of AC. Keep it in terrarium jars. This will not only protect your plant from cold AC air but can also help in maintaining hydration and humidity. 

Inside the jar, Calathea will get warmth. When water vapor gets released, it gets recycled and runs down into the soil.

Maintain Calathea’s health: Cleaning the leaves is essential. Clean the dust from the leaves, remove the spent leaves, stems, and flowers. This will create more space for the plants to grow and reduce the risk of bugs, flies, insects, and diseases.

Also read: Can Indoor Plants Survive In AC? (Suitable Plants+Care)

Final thoughts

Maintaining a suitable temperature for Calatheas is as crucial as the other requirements.

They might tolerate some direct sunlight during the winters, but you should protect them from the cold drafts as Calatheas are sensitive to cold.

The weather condition depends somewhat on the region where you stay. Some regions experience extreme summers, and some regions experience intense winters.

So, you should maintain an ideal temperature for your Calatheas according to the climate. Make sure they are exposed to neither high nor low temperatures.

Provide all the requirements adequately to your Calathea, and you will find them healthy and happy.

Source: NCBI, University of Florida, Wikipedia,  Growing Indoor Plants with Success, Agriculture, and Natural Resources, University of California, Missouri Botanical Garden.