Why Your Snake Plant Has Brown Spots and How to Fix Them

Finding brown spots on your snake plant’s leaves is a common issue that is often correctable. These blemishes are a signal that something in its environment or care routine needs adjustment. The first step is to determine the underlying cause of the spots. By observing the characteristics of the blemishes, you can diagnose the issue and take the appropriate steps to restore your plant’s health.

Identifying the Causes of Brown Spots

A primary reason for brown spots is fungal disease. Infections like rust appear as reddish-brown spots, sometimes with a yellow halo. Another issue, southern blight, causes dark, water-soaked lesions on the leaves. These pathogens thrive when moisture sits on the leaves for extended periods, especially with poor air circulation.

Improper watering is another contributor, leading to root rot. When a snake plant is overwatered, the soil becomes waterlogged and the roots decay. This distress appears as mushy, dark brown or black spots, often starting near the base of the leaves. A foul odor from the soil is another strong indicator of root rot.

Pests can also cause brown marks on the foliage. Insects like spider mites and mealybugs feed on the plant’s tissues, leaving behind damaged areas that scar over. This damage appears as small, pitted, or stippled brown spots. A close inspection of the leaves and plant base can reveal the pests or their fine webbing.

Environmental factors can also cause discoloration. A plant exposed to intense, direct sunlight can get sunburned, resulting in bleached or tan patches. Conversely, exposure to cold drafts or temperatures below 50°F can cause dark, mushy spots. Sudden changes in placement, such as moving a plant from low to high light, can also shock the plant and lead to browning.

How to Treat Brown Spots

Once you identify the source of the brown spots, you can treat the plant. The first step is to remove the damaged tissue to prevent the spread of disease and redirect the plant’s energy. Use sharp, sterilized scissors or a knife to trim away the spots. If more than half of a leaf is damaged, remove the entire leaf at its base.

After pruning, address the specific cause. For fungal infections, apply a fungicide to stop the pathogen’s spread. If you have diagnosed root rot from overwatering, repot the plant. Remove it from its pot, trim away any black, mushy roots, and replant it in a new pot with fresh, well-draining soil.

For pest infestations, treat the plant with an appropriate solution. Manage pests like spider mites and mealybugs by wiping the leaves with a cloth dipped in insecticidal soap or by spraying the plant with neem oil. Be sure to coat all surfaces of the leaves for effective treatment.

Preventing Future Blemishes

Long-term prevention revolves around providing consistent care. Proper watering is a primary way to prevent brown spots, as these succulents are susceptible to overwatering. Use the “soak and dry” method by watering thoroughly and then waiting for the soil to dry out completely before watering again. You can check the soil moisture by inserting your finger a couple of inches deep.

Proper placement and lighting also prevent blemishes. Snake plants do best in bright, indirect sunlight, as direct sun can scorch their leaves. Ensure the plant is not in a location prone to cold drafts from windows or doors. Maintaining good air circulation helps keep the leaves dry and discourages fungal diseases.

Using the correct soil mix provides a healthy foundation. A well-draining potting mix, such as one for cacti and succulents, prevents water from lingering around the roots. A pot with drainage holes is also important for allowing excess water to escape. Avoid excessive fertilizer, as a salt buildup can burn the roots and cause leaf tips to turn brown.