Calathea plants are popular for their striking, intricately patterned foliage. Despite their beauty, these tropical plants are sensitive, and burnt leaves are a frequent concern. This article explores common reasons for burnt Calathea leaves and how to restore plant health.
What Burnt Calathea Leaves Look Like
Burnt Calathea leaves show specific visual cues. Common signs include brown, crispy edges or tips, which can extend into larger browning spots. This discoloration is dry and brittle, distinguishing it from yellowing or soft, mushy spots. These scorched areas indicate damage to the leaf tissue.
Primary Causes of Calathea Leaf Burn
Calathea plants are sensitive to various environmental factors; an imbalance can lead to leaf burn. Understanding the underlying causes is the first step toward effective treatment. Several common issues contribute to this problem, each impacting the foliage distinctly.
Too Much Light
Calatheas naturally grow on the forest floor in tropical regions, receiving dappled, indirect light. Exposing these plants to direct sunlight, even briefly, can scorch their delicate leaves. This excessive light causes leaf tissue to dry out and turn brown, often appearing as bleached or faded spots.
Low Humidity
Originating from humid rainforest environments, Calathea plants require consistently high humidity to thrive. When the surrounding air is too dry, typically below 50-70%, leaf edges and tips lose moisture rapidly, leading to a crispy, brown appearance. This browning often starts at the tips and progresses inward along the leaf margins.
Water Quality/Improper Watering
The quality of water used can significantly impact Calathea health. Tap water often contains salts, chlorine, fluoride, and other minerals that can accumulate in the soil and burn leaf tips. Inconsistent watering, both underwatering and overwatering, also stresses the plant, causing leaf browning. Underwatering dries leaves from the edges, while overwatering can lead to root rot, impacting foliage.
Temperature Extremes
Calatheas prefer stable, warm temperatures, ideally between 18°C and 27°C (65°F and 80°F). Sudden temperature fluctuations, cold drafts, or proximity to heating or cooling vents can stress the plant. This stress can result in leaves curling, drooping, or developing brown edges.
Over-fertilization
Too much fertilizer can cause “fertilizer burn.” Fertilizers contain salts that, in excessive concentrations, draw moisture away from the plant’s roots, causing dehydration. This results in crispy brown leaf edges and tips, similar to underwatering or poor water quality.
Preventing Calathea Leaf Burn
Addressing leaf burn involves adjusting your Calathea’s care routine. Consistent attention to these environmental factors helps maintain healthy foliage. Proactive measures are more effective than attempting to revive damaged leaves.
Optimal Light Placement
Position your Calathea in bright, indirect light to prevent burn. Place the plant a few feet from a window, or use sheer curtains to filter direct sunlight. Avoid spots where direct sunbeams hit the leaves.
Increasing Humidity
Mimicking their native habitat requires increasing the ambient humidity around your plant. You can achieve this by placing the pot on a pebble tray filled with water, ensuring the pot does not sit directly in the water. Using a room humidifier nearby is also effective, or grouping Calatheas with other plants can create a more humid microclimate.
Proper Watering Practices
Use filtered, distilled, or rainwater for your Calathea, as these options lack the harsh minerals found in many tap water sources. Water your plant when the top 1-2 inches of soil feel dry to the touch, ensuring the soil remains consistently moist but never soggy. Always allow excess water to drain completely from the pot’s drainage holes to prevent root issues.
Stable Temperatures
Maintain a consistent room temperature within the preferred range of 18°C to 27°C (65°F to 80°F). Shield your Calathea from sudden drafts caused by open windows, doors, or air conditioning and heating vents. Stable conditions reduce stress on the plant.
Mindful Fertilization
Calatheas do not require heavy feeding. During the growing season (spring and summer), fertilize sparingly, typically once a month, using a balanced liquid houseplant fertilizer diluted to half or even quarter strength. Avoid fertilizing during the dormant winter months, and periodically flush the soil with plain water to prevent salt buildup from fertilizers.
Caring for Affected Calathea Leaves
Once Calathea leaves have brown or crispy areas, they will not regain their green color. To improve appearance and direct energy toward new growth, prune damaged foliage. Use clean, sharp scissors or shears to remove severely burnt leaves at their base. For leaves with only browned tips, carefully trim away the affected edges, following the natural shape. While trimming improves aesthetics, addressing the underlying cause of the burn is essential to prevent future damage.