Snake plants (Sansevieria trifasciata) are popular, low-maintenance houseplants known for their striking foliage and resilience. Despite their hardy reputation, brown spots can appear on their leaves. Understanding the causes is key to restoring plant health.
Understanding Common Causes
Brown spots on snake plant leaves can stem from various environmental factors or care practices. Overwatering is a frequent culprit, as consistently soggy soil deprives roots of oxygen, leading to root decay. This root damage inhibits the plant’s ability to absorb water and nutrients, causing parts of the leaves to brown and soften. Conversely, prolonged underwatering can also cause issues; when the plant experiences severe dehydration, leaf tips and edges may become dry and crispy, eventually turning brown.
Excessive light exposure, particularly direct sunlight, can scorch snake plant leaves, manifesting as brown, burnt patches. Cold temperatures and sudden drops can harm the plant’s tissue, resulting in dark, water-soaked brown spots or blackened areas. Fungal infections, such as brown blotch or leaf spot, thrive in humid conditions with poor air circulation, causing distinct brown lesions on the foliage. Physical damage from bumps, scrapes, or bending can also lead to localized browning as the bruised tissue dies.
Diagnosing the Problem
Identifying the specific cause of brown spots requires careful observation of the spots’ characteristics and accompanying plant symptoms. If the brown spots are soft, mushy, and appear primarily at the base or randomly on the leaves, often accompanied by a foul odor from the soil, overwatering and potential root rot are likely. Conversely, if the brown areas are crispy, dry, and typically located at the leaf tips or edges, the plant may be suffering from underwatering.
Sunburn spots usually appear as dry, bleached, or crispy brown patches, often on the parts of the leaves most exposed to direct light, feeling papery to the touch. When cold damage occurs, the affected areas will often be dark brown or black, appearing water-soaked or sunken. Fungal infections, like brown blotch, present as distinct, irregular yellowish-brown spots that can enlarge and merge, sometimes with a visible border or halo and a slightly sunken appearance. If the browning is isolated to a specific area and appears as a bruise that has darkened, physical damage is the probable cause.
Treatment and Prevention Strategies
Addressing brown spots on snake plants involves adjusting care practices. For overwatering, allow the soil to dry out completely between waterings, checking moisture levels with a finger. Ensure the pot has adequate drainage holes and consider repotting into a well-draining succulent or cactus mix if the current soil retains too much moisture. If underwatering is the issue, establish a more consistent watering routine, ensuring the plant receives a thorough drink when the top few inches of soil are dry.
To prevent sunburn, relocate the plant to a spot with bright, indirect light, away from direct sun exposure, especially during the strongest parts of the day. Protect the plant from cold damage by moving it away from drafty windows or vents during colder months and maintaining a stable indoor temperature, ideally between 65-80°F (18-27°C). For fungal infections, improve air circulation around the plant and avoid getting water on the leaves when watering. Affected leaves should be pruned using sterilized tools to prevent spread, and a fungicide can be applied in severe cases. These plants are highly drought-tolerant, so it is safer to underwater slightly than to overwater.