Why are Calathea Leaves Turning Yellow? Causes, Remedies, and Expert Advice

5/5 - (12 votes)

Why Are Calathea Leaves Turning Yellow

Calathea leaves turning yellow can alarm even the most experienced plant enthusiasts. Known for their vibrant, patterned foliage, Calatheas lend stunning beauty to any indoor garden. So, when these lush leaves begin to yellow, it’s a sign something is amiss.

Is it overwatering? Improper light? Or, perhaps, it’s something a bit more complex? We’re going to delve into the intriguing world of Calatheas, discovering the potential causes behind this concerning discoloration.

Why Are Calathea Leaves Turning Yellow?

1. Overwatering

Description causes root rot, leading to nutrient deficiency and chlorophyll breakdown, resulting in yellowing leaves.
Solution Reduce watering and ensure proper drainage to prevent roots from sitting in excess water.

Overwatering is often to blame when Calathea leaves turn yellow. When overwatered, your plant struggles with root rot, a condition that, if left unchecked, can kill the plant. Root rot inhibits the plant’s ability to absorb water and nutrients from the soil, causing your Calathea’s leaves to turn yellow.

To solve this issue, you need to adjust your watering schedule. Make sure the top inch of soil dries out before you water again. If the plant is severely overwatered and the situation is dire, consider repotting your Calathea in fresh, well-draining soil. Always remember to use pots with proper drainage holes. Additionally, refrain from using harsh tap water; instead use rainwater, distilled water, or tap water that has been left to sit overnight.

Monitor the plant closely for recovery. It might take a few weeks before you see improvement. During this procedure, note that Calatheas prefer high humidity as they originate from tropical areas, and they enjoy bright but indirect sunlight. Testing your soil’s moisture levels can prove beneficial in preventing overwatering in the future. Aim to keep the plant in an environment with even, warm temperatures. Careful monitoring and adjustments can help restore your overwatered Calathea to health.

2. Underwatering

Description causes insufficient water uptake, leading to chlorophyll breakdown and yellowing of the leaf.
Solution Water the plant more frequently to prevent dehydration and restore healthy green color to leaves.

Calathea plants are tropical indoor plants that require ample water to thrive. When these plants are underwatered, they may show signs of stress such as yellowing leaves. Underwatering means the plant is unable to get the necessary nutrients and moisture to maintain the green vividity of its leaves. Lack of water also inhibits the plant’s ability to photosynthesize properly, causing discoloration.

To address underwatering, implement a more regular watering schedule. Calathea plants love moist soil—so aim to water them at least once a week, depending on the humidity and temperature in your home. Just avoid overwatering, as it can lead to root rot. Mulching can also be beneficial in retaining soil moisture.

Using well-draining soil is another excellent approach to help your Calathea plant recover, as it ensures the right balance of moisture. Expert Care Tip: Calathea plants do not only need proper watering, adequate light and a balanced fertilizer are also crucial in maintaining the healthy color and growth of the leaves.

3. Lack of sunlight

Description The lack of sunlight causes the Calathea leaves to turn yellow due to reduced chlorophyll production.
Solution Increase sunlight exposure for Calathea leaves to prevent yellowing.

Calathea plants are tropical species that thrive in a partially shaded environment. Exposure to direct sunlight may cause the leaves to turn yellow. This is because the intense light causes the water in the leaves to evaporate too quickly, leading to dehydration and consequently yellowing.

Solution to address this includes moving your Calathea plant away from direct sunlight, if it is situated near a south or west-facing window. Indirect sunlight or filtered light is more suitable for this type of plant. You might also want to check the intensity of light throughout the day and adjust the plant’s position accordingly. Spreading sheer curtains on your windows can also serve as an effective way of filtering the light.

4. Nutrient deficiency

Description The lack of sunlight causes the Calathea leaves to turn yellow due to reduced chlorophyll production.
Solution Increase sunlight exposure for Calathea leaves to prevent yellowing.

When Calathea leaves turn yellow, one possible cause could be a nutrient deficiency. The plant may not be getting enough essential elements such as nitrogen, iron, or magnesium. This is because each of these nutrients plays a crucial role in plant health. For example, nitrogen is instrumental in promoting leaf growth, a deficiency of which leads to chlorosis, a condition that manifests as yellow leaves. Similarly, iron and magnesium are key for photosynthesis; their deficiency also results in leaf yellowing.

To rectify this problem, you can apply a balanced liquid fertilizer during your regular watering routine, ensuring all the essential nutrients are provided. Moreover, adding organic matter to your soil can also improve its nutrient content. Also, adjust your watering strategy if you find the plant is waterlogged, as this can further inhibit nutrient absorption. But remember, before administering any nutrient supplements, it may be beneficial to get your soil tested to better understand its specific nutrient needs.

Why Are Calathea Leaves Turning Yellow

5. Pests or diseases

Description Increase sunlight exposure for Calathea leaves to prevent yellowing.
Solution Apply organic pesticide to eliminate pests or treat with appropriate fungicide to address diseases.

Calathea leaves turning yellow could be a result of pest infestations or diseases. Pests like spider mites, aphids, or mealybugs can suck the juice out of the leaves, making them turn yellow and wilt. Fungal or bacterial diseases can also cause discoloration and wilting, often resulting from overwatering or poor air circulation.

To treat pest infestations, it is advisable to use natural insecticides or insecticidal soaps. In severe cases, stronger commercial products might be necessary. Always ensure to maintain sanitary conditions by getting rid of any dead leaves or debris that can harbor pests.

For diseases, ensure the plant is not overwatered or left in standing water. Good air circulation is important to prevent fungal infections. If the plant is diseased, isolate it to prevent the disease from spreading to other plants. In severe cases, you may need to use a suitable fungicide or bactericide.

6. Temperature stress

Description The yellowing of Calathea leaves is caused by temperature stress affecting their physiological processes.
Solution Adjust temperature to optimal range and provide consistent humidity levels to prevent yellowing of leaves.

When Calatheas are exposed to temperature stress, this can result in their leaves turning yellow. Essentially, Calatheas are tropical plants that thrive in warmer conditions and when they are exposed to temperatures that are too cold or too hot, it causes them stress which can lead to yellowing leaves.

As a solution, maintain ideal temperature conditions within the range of 65-85°F (18-29°C), as fluctuation outside of this range can be detrimental. Avoid places with drafts and sudden temperature changes, like near air conditioning vents or outside doors. To create a humid environment, mist the leaves regularly or place the pot on a tray filled with pebbles and a little water.

Keep in mind that right lighting conditions are also essential to manage temperature stress. These plants prefer bright, indirect sunlight. Too much direct sunlight can burn the leaves, leading to yellow spots, while too little light can cause the plant to lack vitality.

Regular monitoring of the plant’s environment is key in dealing with this issue. If yellowing persists, consider talking to a local horticulture expert for advice, as there might be other contributing factors such as overwatering or nutrient deficiencies.

7. Aging or natural leaf cycle

Description Chlorophyll breaks down, revealing other pigments, as part of the natural leaf cycle.
Solution Increase watering frequency, provide proper lighting, and prune dead leaves regularly to extend leaf lifespan.

The reason for Calathea leaves turning yellow can be due to inadequate watering. Calathea plants are native to tropical environments, so they require a significant amount of water to thrive. However, providing either too much or too little can cause their leaves to turn yellow. Overwatering can lead to root rot, which deprives the plant of essential nutrients, resulting in yellow leaves. On the other hand, underwatering causes the plant to dry out, leading to a similar yellowing effect.

To resolve this issue, it’s crucial to implement a consistent watering routine tailored to the plant’s needs. Allow the top one to two inches of soil to dry out between watering. When it’s time to water, do so thoroughly until water drains from the bottom of the pot, ensuring the roots receive enough hydration. From there, you must wait until the soil is sufficiently dry before repeating the process. A regular inspection of plant health can also aid in early detection of watering problems, so adjustments can be made timely.