The Rubber Fig (Ficus elastica) is a hardy houseplant, but brown spots on its leaves can signal underlying issues. From the plant's perspective, these spots are distress signals caused by environmental stress, pests, or diseases. Understanding the causes and addressing them promptly ensures the plant's vitality.
2.1 Overwatering or Poor Drainage
Rubber Figs dislike soggy soil. Excess water suffocates roots, leading to root rot, which manifests as brown spots on leaves. The plant's roots cannot absorb oxygen, triggering cellular damage in leaf tissues.
2.2 Underwatering or Low Humidity
Inconsistent watering or dry air causes dehydration. Leaf cells collapse, creating dry, crispy brown patches, often starting at the edges. The plant prioritizes survival by sacrificing older leaves.
2.3 Sunburn
Direct sunlight scorches leaves, causing brown, bleached spots. The plant's chlorophyll breaks down under intense light, damaging photosynthetic tissues.
2.4 Pest Infestations
Spider mites or scale insects pierce leaf cells to feed, leaving brown speckles. The plant responds by sealing wounded areas, resulting in localized necrosis.
2.5 Fungal or Bacterial Infections
Pathogens like Cercospora or bacterial leaf spot invade through wounds or wet foliage. The plant's immune response isolates infections, forming brown lesions with yellow halos.
3.1 Adjust Watering Practices
Water only when the top 2 inches of soil are dry. Ensure pots have drainage holes to mimic the plant's natural preference for well-aerated soil.
3.2 Optimize Humidity
Mist leaves or use a pebble tray to maintain 40-60% humidity. This replicates the plant's tropical habitat, preventing dehydration.
3.3 Provide Indirect Light
Place the plant in bright, filtered light. If sunburn occurs, relocate it gradually to avoid further stress.
3.4 Pest Management
Wipe leaves with neem oil or insecticidal soap. The plant benefits from reduced pest pressure, allowing it to redirect energy to growth.
3.5 Treat Infections
Prune affected leaves and apply fungicides if needed. Sterilize tools to prevent spreading pathogens, supporting the plant's recovery.
4.1 Regular Inspection
Monitor leaves weekly for early signs of stress. The plant thrives when issues are caught before severe damage occurs.
4.2 Balanced Fertilization
Use a diluted, balanced fertilizer during growing seasons. Over-fertilization harms roots, while under-fertilization weakens the plant's defenses.
4.3 Proper Potting Mix
Use well-draining soil with perlite or orchid bark. This mimics the plant's native epiphytic conditions, promoting healthy root function.
