Why Are My Calathea Leaves Turning Yellow? 7 Causes, Solutions & Best Care Tips

Calathea plants are popular for their stunning foliage, but it can be frustrating to see their leaves turn yellow. Yellowing leaves are a common problem with Calathea plants, and there are several possible causes. Understanding the reasons behind this issue is crucial to maintain the health of your plant.

Some of the most common causes of yellowing leaves in Calathea plants include overwatering, underwatering, temperature extremes, low humidity levels, pests, and diseases. Each of these issues presents with differing symptoms and requires different solutions.

A detailed examination of the causes can help you better understand how to prevent and treat yellowing leaves in your Calathea plant.

Key Takeaways on Calathea Leaves Turning Yellow

• Proper watering is crucial for the health of Calathea plants.
• Light and temperature levels, humidity, pests, diseases, and nutrient management can all contribute to yellowing leaves in Calathea plants.
• Regular care and maintenance, including soil and pot considerations, can help prevent yellowing leaves and keep your Calathea plant healthy.

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Understanding Calathea Plants

Calathea plants are popular houseplants known for their vibrant foliage and unique patterns. These tropical plants are native to South America and require specific care to thrive indoors. Understanding the needs of Calathea plants is crucial to prevent issues like yellowing leaves.

Calathea plants are part of the Marantaceae family and are often called prayer plants due to their habit of folding their leaves up at night. They come in a variety of species and cultivars, each with its unique leaf shape, color, and pattern. Calathea plants prefer bright, indirect light and thrive in high humidity environments.

One of the most common issues with Calathea plants is yellowing leaves. This can be caused by a variety of factors, including overwatering, underwatering, temperature fluctuations, low humidity, pests, and diseases. It’s essential to identify the cause of yellowing leaves to prevent further damage to the plant.

Calathea plants can be sensitive to changes in their environment, so it’s crucial to maintain consistent care. They prefer well-draining soil that’s kept moist but not soaked. It’s essential to avoid letting the plant sit in standing water, as this can lead to root rot and yellowing leaves.

Calathea Leaves Turning Yellow – 5 Common Problems

Calathea is a beautiful plant that can add a pop of color to any room. However, it can be frustrating when the leaves start turning yellow. Yellowing leaves can be a sign of various issues, including watering problems, light and temperature factors, humidity levels, pest infestations, and nutrient deficiencies.

Understanding the common causes of yellow leaves can help you identify and fix the problem.

1. Watering Issues

Overwatering is one of the most common causes of yellow leaves in Calathea. When the roots are constantly wet, they cannot absorb enough oxygen, causing the leaves to turn yellow and eventually die.

On the other hand, underwatering can also cause yellowing leaves. When the soil is too dry, the plant cannot absorb enough water and nutrients, leading to yellow spots on the leaves.

To avoid overwatering or underwatering, it is essential to check the soil moisture regularly. Water the plant only when the top inch of soil is dry to the touch. Also, make sure the pot has proper drainage to avoid waterlogging.

2. Light and Temperature Factors

Calathea prefers bright, indirect light. Direct sunlight can scorch the leaves and cause yellowing. On the other hand, insufficient light can also cause yellowing leaves. Additionally, temperature extremes can stress the plant and cause yellow spots on the leaves.

To avoid light and temperature-related issues, place the plant in a bright spot away from direct sunlight. Keep the temperature between 65°F and 80°F and avoid exposing the plant to cold drafts.

3. Humidity Levels

Calathea thrives in high humidity levels. Low humidity levels can cause the leaves to curl and turn yellow. Additionally, dry air can attract pests, leading to further damage.

To maintain high humidity levels, mist the leaves regularly, or place a humidifier near the plant. You can also place a tray of water near the plant to increase the humidity around it.

4. Pest Infestations

Pests like spider mites and mealybugs can infest Calathea, causing yellowing leaves. These pests feed on the plant’s sap, causing damage to the leaves.

To avoid pest infestations, inspect the plant regularly for signs of pests. If you notice any pests, isolate the plant and treat it with an appropriate pesticide.

5. Nutrient Deficiencies

Calathea requires specific nutrients to thrive, including nitrogen, phosphorus, and potassium. A deficiency in any of these nutrients can cause yellowing leaves.

To avoid nutrient deficiencies, fertilize the plant regularly with a balanced fertilizer. Follow the manufacturer’s instructions for application and frequency.

Detailed Examination of Causes

Calathea leaves turning yellow can be a sign of various problems. A detailed examination of the causes can help identify the issue and take the necessary steps to save the plant.

1. Overwatering

Overwatering is one of the most common reasons for Calathea leaves turning yellow. When the soil is too wet, the roots cannot absorb the nutrients properly, leading to yellow leaves. Additionally, overwatering can cause root rot, which can be fatal for the plant.

2. Underwatering

Underwatering can also cause yellowing of Calathea leaves. When the soil is too dry, the plant cannot get the required nutrients, leading to yellowing of the leaves.

3. Light Conditions

Calathea plants prefer bright, indirect light. Direct sunlight can scorch the leaves and cause yellowing. On the other hand, low light conditions can also cause yellowing of the leaves.

4. Humidity

Calathea plants require high humidity levels to thrive. Low humidity can cause the leaves to turn yellow and dry out.

5. Pest Infestations

Spider mites are a common pest that can infest Calathea plants. They feed on the plant’s sap, causing yellowing and other damage to the leaves.

6. Nutrient Deficiency

Calathea plants require certain nutrients to grow and thrive. A lack of iron, nitrogen, or magnesium can cause yellowing of the leaves. Additionally, high levels of chlorine or fluoride in the water can also cause yellowing.

7. Diseases

Fungal infections can cause yellowing of the leaves in Calathea plants. These infections can be caused by overwatering, poor soil, or insufficient light.

8. Temperature Fluctuations

Calathea plants prefer consistent temperatures and do not tolerate cold temperatures well. Temperature fluctuations can stress the plant and cause yellowing of the leaves.

9. Nutrient Imbalance

Over-fertilizing or using the wrong type of fertilizer can cause yellowing of the leaves. Additionally, a soil pH that is too high or too low can also cause yellowing.

The Role of Proper Watering

Proper watering is crucial for the health of a Calathea plant. Overwatering or underwatering can both cause the leaves to turn yellow.

Overwatering and Root Rot

Overwatering is one of the most common reasons for yellowing leaves in Calathea plants. When the soil is consistently moist, the roots can’t get enough oxygen, which leads to root rot. Root rot damages the roots and prevents them from absorbing nutrients, causing the plant to wilt and the leaves to turn yellow.

To prevent overwatering, make sure the plant’s pot has drainage holes to allow excess water to escape. When watering, allow the water to drain completely before placing the pot back in its saucer. Also, avoid using tap water, as it may contain minerals that can accumulate in the soil and damage the roots.

Underwatering and Drought Stress

Underwatering is another common cause of yellowing leaves in Calathea plants. When the soil is too dry, the roots can’t absorb enough water, causing the plant to wilt and the leaves to turn yellow.

To prevent underwatering, make sure the soil is moist but not waterlogged. Check the moisture level by sticking your finger into the soil up to the first knuckle. If the soil feels dry, it’s time to water the plant. Also, make sure to water the plant on a regular schedule, as irregular watering can cause drought stress and damage the roots.

Importance of Light and Temperature

Calathea plants are native to tropical regions and require a consistent temperature and humidity level to thrive. Temperature fluctuations can cause stress to the plant, leading to yellowing leaves. It is important to keep the plant in a warm and humid environment, with temperatures between 65°F to 80°F (18°C to 27°C).

Light is also a critical factor in the health of Calathea plants. They require bright, indirect light, but direct sunlight can scorch their leaves. Too much shade can also cause yellowing leaves and stunted growth.

It is recommended to keep the plant in a spot that receives indirect light for most of the day, although they can tolerate some direct morning sunlight.

If the plant is not receiving enough light, it can cause the leaves to turn yellow. This is because the plant is not producing enough chlorophyll, which is responsible for the green color of the leaves. If the plant is receiving too much light, it can cause the leaves to burn and turn yellow or brown.

It is important to keep the plant in a consistent environment with stable light and temperature levels. Sudden changes in temperature or light can cause stress to the plant, leading to yellowing leaves. A consistent and stable environment can help prevent this issue and keep the plant healthy.

Maintaining Humidity Levels

Calathea plants are native to tropical regions and thrive in humid environments. Maintaining proper humidity levels is crucial for the health of the plant. Low humidity levels can cause the leaves to turn yellow and eventually die. On the other hand, high humidity levels can lead to fungal growth and other issues.

To maintain the proper humidity levels, it is recommended to keep the plant in a room with a humidity level of 50% or higher. If the room’s humidity level is low, it can be increased by using a room humidifier or by placing a tray of water near the plant. This will help to increase the humidity levels around the plant.

Another way to increase humidity is to mist the leaves of the plant regularly. This is especially important during the winter months when the air tends to be drier. Misting the leaves will help to keep them hydrated and prevent them from turning yellow.

It is important to note that while misting can help increase humidity levels, it should not be relied upon as the sole method of maintaining proper humidity levels. In addition to misting, using a room humidifier or placing a tray of water near the plant can also help to maintain proper humidity levels.

Dealing with Pests and Diseases

Calathea plants are susceptible to pests and diseases, which can cause yellowing of leaves. Common pests that infest Calathea plants include spider mites and mealybugs.

Spider mites are tiny pests that suck the sap from leaves, causing yellowing and curling. Mealybugs, on the other hand, are small, white insects that feed on the sap of plants, causing yellowing and stunted growth.

To treat pest infestations, it is important to identify the type of pest that is causing the problem. Spider mites can be controlled by spraying the plant with a solution of water and neem oil. Mealybugs can be removed by wiping the leaves with a cotton swab dipped in rubbing alcohol.

Fungal infections, such as Grey Mold and Bacterial Leaf Spots, are two prevalent diseases in Calathea. These diseases can cause yellowing of leaves and other symptoms, such as wilting and rotting. To prevent fungal infections, it is important to avoid overwatering the plant and to ensure that it is planted in well-draining soil.

If a fungal infection does occur, it is important to remove the infected leaves and treat the plant with a fungicide. Copper-based fungicides are effective in treating fungal infections in Calathea plants.

Nutrient Management

Calathea plants require proper nutrient management to maintain their health and prevent yellowing leaves. Nutrient deficiencies can cause yellowing of leaves, but over-fertilizing can also have the same effect.

Fertilizer is essential for healthy plant growth. However, it is important to use the right type and amount of fertilizer. A balanced fertilizer with equal amounts of nitrogen, phosphorus, and potassium is recommended. Over-fertilizing can cause salt build-up in the soil, which can lead to yellowing leaves.

Iron deficiency is a common cause of yellowing leaves in Calathea plants. Iron is essential for chlorophyll production, which gives leaves their green color. A lack of iron can cause chlorosis, which is the yellowing of leaves. Iron supplements can be added to the soil to correct this issue.

Nitrogen is another important nutrient for plant growth. It is responsible for leaf and stem growth. A lack of nitrogen can cause stunted growth and yellowing of leaves. However, too much nitrogen can also cause yellowing of leaves. It is important to use the right amount of nitrogen fertilizer.

Magnesium is also important for plant growth. It is essential for the production of chlorophyll. A lack of magnesium can cause yellowing of leaves. Epsom salt can be added to the soil to correct this issue.

Chlorine and fluoride are two nutrients that can cause yellowing of leaves if present in high amounts. Tap water can contain high levels of chlorine and fluoride. Using distilled or rainwater can help prevent yellowing of leaves.

Liquid fertilizer can be used to provide plants with essential nutrients. However, it is important to follow the instructions on the label and not over-fertilize. Over-fertilization can cause salt build-up in the soil, which can lead to yellowing leaves.

Soil and Pot Considerations

The soil and pot considerations are crucial for maintaining the health of Calathea plants. The right potting mix, soil pH, and pot size can make all the difference in preventing yellowing leaves.

Calathea plants prefer slightly acidic soil with a pH range of 6.0 to 6.5. If the soil pH is too high, it can cause nutrient deficiencies, leading to yellowing leaves. To ensure the soil is slightly acidic, gardeners can mix peat moss or coco coir into the potting mix.

Well-draining soil is also essential for Calathea plants. The roots need oxygen to grow, and if the soil is too heavy or compacted, the roots can suffocate and die. Gardeners can improve the soil drainage by adding perlite, bark, or mulch to the potting mix.

The pot size and type are also important considerations. Calathea plants prefer to be slightly root-bound, so it’s best to choose a pot that’s only slightly larger than the plant’s root ball. If the pot is too large, the soil can become waterlogged, leading to root rot and yellowing leaves. Additionally, the pot should have drainage holes to allow excess water to drain out of the soil.

When repotting Calathea plants, gardeners should use fresh potting soil and remove any dead or damaged roots. It’s also important to check the roots for signs of root rot, which is a common problem in poorly-draining soil. If the roots are brown and mushy, it’s best to trim them back to healthy tissue and repot the plant in fresh soil.

Practical Care Tips

To prevent Calathea leaves from turning yellow, it is crucial to provide the plant with proper care. Here are some practical care tips to help keep your Calathea healthy and vibrant.

1. Watering

One of the most common reasons for yellowing leaves is overwatering. Calathea plants prefer slightly moist soil, but they do not like to sit in water. It is essential to allow the top inch of soil to dry out before watering again.

Using a moisture meter can help determine when the soil is dry enough for watering. Additionally, using a water filtration system can prevent the buildup of minerals in the soil, which can cause leaf discoloration.

2. Humidity

Calathea plants thrive in high humidity environments, as they are native to tropical rainforests. Low humidity can cause the leaves to curl and turn yellow. To increase humidity levels, place a humidifier near the plant or group it with other plants to create a microclimate.

Alternatively, placing a tray of water near the plant can also help increase humidity levels.

3. Lighting

Calathea plants prefer bright, indirect light. Direct sunlight can scorch the leaves and cause them to turn yellow. If the plant is not getting enough light, it may also cause the leaves to turn yellow. If the plant is not getting enough light, move it to a brighter location, but avoid direct sunlight.

4. Pruning

Pruning can help keep the Calathea plant healthy and promote new growth. Use a clean pair of pruning shears to remove any dead or yellowing leaves. It is also essential to remove any leaves that are touching the soil, as they can cause the plant to become infected with disease.

5. Environmental Changes

Environmental changes, such as temperature fluctuations or drafts, can cause stress to the Calathea plant and cause the leaves to turn yellow. It is essential to keep the plant away from any air conditioning vents or drafty areas. Additionally, avoid placing the plant near any heat sources, such as radiators or heaters.

Frequently Asked Questions