How to Fix Calathea Yellow Leaves?

Calathea beautifies your house with its glossy, attractive green leaves. Also, it will be sad to see Calathea’s leaves turning yellow.

If you catch the symptoms in their early stages, you will have a great chance of returning to plant health.

Therefore, please read the article further to know what causes Calathea yellow leaves and how to fix them.

What Causes Calathea Leaves to Turn Yellow? How to Fix 

People have used Calathea plants as indoor decorative plants since the 1970s and 1980s after finding them in the wild and domesticating them.

As an indoor plant, Calathea has specific care requirements that you must fulfill to keep it healthy. Any anomaly will cause stress in your plant.

1. Improper Watering

Calathea is a tropical plant that can be fussy about watering.

Incorrect watering, both over and underwatering, may jeopardize its health, resulting in yellowing leaves.

Underwatered Calathea

Calathea plants require adequate watering to reach the desired height.

Due to environmental factors or negligence, you may water your plant less frequently than necessary. Calathea will show yellow leaves to indicate stress in such cases.

Underwatering the plant prevents the roots from transporting nutrients from the soil to the plant resulting in yellowing leaves.

Other signs of underwatering include droopy leaves, bone-dry soil, brown-dried leaves, and so on.

Immediate Steps of Revival

• The first step is the ‘soak and dry’ method. Fill a tub with water and immerse the pot until the bubbles stop forming in the water.
• Another method is to place the plant on a water-filled pebble tray. The plant will soak water slowly, and the weak roots won’t suffer.
• Place your plant in a shady area, so the remaining moisture is not lost.
• Water the plant thoroughly until water leaks out of the drainage hole.

Overwatered Calathea

Overwatering is the most prevalent cause that invites problems in houseplants.

The leaves of the Calathea plant can turn yellow if it gets too much water. In extreme cases, overwatering can cause root rot in the plant.

Too much water in the root zone can impair the plant’s oxygen absorption.

In the plant’s dormancy, i.e., winter, you must reduce the watering frequency to avoid oversaturating the root area.

Additionally, waterlogging can encourage fungi and other harmful organisms, leading to pest infestation.

Other symptoms of overwatering include limpy stems, droopy leaves, leaf tips turning brown, etc.

Immediate Steps of Revival

• Immediately stop watering your Calathea plant and let it heal from the effect of overwatering.
• Take your Calathea plant out of the pot and scrutinize the rootball. Remove the brown and mushy roots.

While snipping off the rotten roots, make sure you do not hurt the healthy roots.

• If the situation worsens, repot your Calathea in a fresh potting mix. Make sure to choose a pot with suitable drainage holes.
• Place the pot in a place with enough bright indirect light so that the soil dries up faster.
• Use proper fungicides to treat the root rot and avoid the spread to other healthy roots.
• Move your plant to a shady area so that the upper leaves do not incur any damage.

Moreover, poor-quality water can also contribute to the yellowing of Calathea leaves. The fluoride and chloride in tap water can damage the plant tissues and cause them to turn yellow.

Unfortunately, the necrosis caused by fluoride and chloride toxicity is irreversible, so you may cut the yellow leaves off.

However, rain or distilled water can keep the Calathea leaves from getting yellow.

2. Improper Lighting

Calathea is accustomed to living in brightly lit areas under the canopy of huge trees.

So, for the optimal growth of your plant, you need to provide it with a bright light shaded by curtains or drapes.

Calathea leaves can turn yellow if they are exposed to too much sunlight or suffer from a lack of light.

The plant cannot perform photosynthesis in low-light conditions, reducing the amount of chlorophyll. As a result, a lack of this green pigment can cause the yellowing of the leaves.

Similarly, in harsh lights, the chlorophyll in the leaves will break down, and then the leaves will turn yellow.

High light intensity also increases the transpiration rate in leaves, which causes the plant to dehydrate quickly, resulting in yellow leaves.

Calathea exhibits additional symptoms due to poor lighting, which I have listed in the table below.

Immediate Steps of Revival

• Move your plant 6 feet from the window to avoid excessive light damage.
• Shield the plant from direct sunlight by keeping it on windows with drapes or curtains.
• Trimming the leaves off the plant with sterilized equipment is safe if the leaves have turned brown.
• In case of low light damage, move the plant to a brighter room to provide optimum brightness.
• In case of low light conditions, you can place your plant with artificial grow lights for about 16 hours.

3. Improper Fertilization 

The Calathea plant does not require heavy feeding, but will still do good specific nutrients to boost its growth.

Generally, if the Calathea plant gets too much fertilizer, the salt in fertilizers will turn its leaf yellow.

Meanwhile, house plants require two nutrients for better functioning: Micronutrients and Macronutrients.

The lack or abundance of these chemicals can stress and even kill your plant.

Under-fertilization symptoms include poor new growth, wilting foliage, and underdeveloped roots.

Similarly, too much fertilizer will render symptoms like stunted growth, burnt leaf margins, and even plant death.

Immediate Steps of Revival

• In case of overfertilization, leach your plant, remove the excess salt build-up, and wash off the surface with high-pressure water.
• Do not fertilize the plant unless it recovers appropriately, and avoid feeding it in the fall and winter.
• If the soil has gone wrong with too much fertilizer, you must repot the plant in another container with fresh potting soil.
•  You can use nutrient-rich 10-10-10 fertilizers like Organic Indoor Plant Food, Joyful Dirt, and Miracle-Gro if the plant lacks nutrients,
• Mix half a teaspoon of fish or kelp meal in nearly one liter of water and water your plant.
• You can also use compost, and homemade fertilizer may reduce the need for chemical fertilizers.

4. Temperature Stress and Low Humidity

The Calathea plant may become stressed and produce yellow leaves when exposed to cold winds, low temperatures (below 60°F), and low humidity (below 50%).

Generally, the Calathea plant prefers a temperature between 60°F to 85°F. The plant’s foliage will burn from the edges if the temperature exceeds the preferred range.

Additionally, since your plant prefers a higher humidity level, you must keep the humidity level above 50%.

Higher humidity levels will not harm the plant, but too little humidity will cause its leaves to turn yellow.

Whereas low humidity will slow the plant’s growth and cause the abscission of leaves.

Other low temperatures and humidity symptoms include decreased photosynthesis activity, leaf curling, stunted growth, etc.

Immediate Steps of Revival

• Mist the plant immediately if it shows any of the above symptoms.
• It would be best to move your plant indoors to protect it from extreme temperature damage during the summer.
• Keep your plant on top of a heating pad to keep them warm during the winter.
• Place the plant under the incandescent grow light if the temperature decreases.
• Prepare a mini greenhouse for your plants to provide them with natural warmth.
• Move your plants away from air conditioning vents, buy a humidifier, or keep a wet pebble tray under the plant.
• Check the plants for pests and infections and group them with other plants to let them share humidity naturally.

5. Improper Soil and Repotting Shock

Calathea’s natural habitat is loamy forest soil. As a result, you should mimic their similar growing condition for them. 

If prefers moist, well-draining yet water-retaining soil that is slightly acidic and rich in nutrients.

Yellow Calathea leaves can be caused by compact soil that has poor drainage and cannot retain moisture.

Similarly, repotting shock can also result in yellow foliage. This is because the plant’s surroundings and soil are not ideal, which causes it to shrink and develop yellow leaves.

On the other hand, excessive root pruning, fungal disease, cold temperatures, or a damaged root system may cause repotting shock.

Similarly, if the soil is not optimal for the plant, the plant’s uptake of nutrients and water is hampered, which causes the leaves to turn yellow.

Other symptoms of improper soil and repotting shock include slow growth, wilting, leaves curling, plant dieback, etc.

Immediate Steps of Revival

• If the plant is going through transplant shock, let it be. It may take some time to get accustomed to the environment.
• Scrutinize the soil; if it has gone too bad, repot it in fresh, well-draining loamy soil that retains moisture.
• Provide optimum care to the plant, like before the repotting, and place it in a location with optimum light.

To avoid repotting stress, repot the plant in early spring, once a year, in a pot about 2 inches bigger than the current pot.

6. Infestation of Pests and Diseases 

Due to anomalies in different conditions, Calathea can sometimes invite certain pests and infections that can even result in the plant’s death.

Pests like spider mites, mealy bugs, scales, thrips, and diseases like root rot and Fusarium can cause Calathea leaf yellowing.

The pests feed on the plant’s juices and hinder their nutrient uptake, which causes the leaves to turn yellow.

Likewise, root rot congests the soil and blocks the passing of nutrients and water to the leaves. Fusarium is also a prime cause of the yellowing and wilting of the plant.

Immediate Steps of Revival

• To avoid further spread, isolate the infected parts from the plant.
• Get insecticidal soap and wash the plant with it. You can also spray neem oil on the foliage to control pest infestation.
• Keep the plant separate from other healthy plants to avoid spreading diseases and pests.
• Dilute rubbing alcohol in water and wipe the leaves of the plants to get rid of pests.
• In case of root rot, take the root ball out of the pot and inspect the roots. Trim away the brown and mushy roots and repot the plant in fresh potting soil if necessary.
• For Fusarium disease, treat the plant with proper fungicides.
• If the plant cannot be saved, dispose of it safely and sterilize the pot.

7. Natural Life Cycle

Your Calathea plant can survive for forty years if you provide good care.

As the plant approaches its old age, the lower leaves of the plant start to fall off to make way for newer growths.

Before falling to their demise, the older bottom leaves of the Calathea plant turn yellow.

This is a natural process and does not mean the plant is stressed.

It is entirely up to you to leave them on the plant or prune them.

They will eventually fall off if you let them stay on the plant. But not pruning them means wasting your valuable plant resources on them.

Should I Cut Yellow Leaves Off the Calathea?

After your Calathea plant has incurred yellow leaves, it has less chance of recovering and reverting to its original form. If the entire leaf turns yellow, it will eventually fall off.

However, cutting off the plant’s yellow leaves with sterilized scissors or pruning shears would be best.

If you keep the yellow leaves intact, the plant cannot focus its energy on the new growths.

Also, yellow leaves may be a blemish to the perfect aesthetic provided by this plant.

If there are only a few yellow spots on the leaves, you may be able to nurse the plant back to health.

Watch the full video for more tips,