Root rot is a common but serious issue affecting rubber plants (Ficus elastica), often caused by overwatering or fungal pathogens like Pythium or Phytophthora. From the plant's perspective, root rot disrupts nutrient and water uptake, leading to systemic stress. Understanding the signs and treatment is crucial for restoring plant health.
Rubber plants exhibit several distress signals when suffering from root rot:
2.1 Yellowing Leaves: The plant prioritizes survival, sacrificing older leaves as nutrient uptake fails. Chlorosis (yellowing) starts at the lower leaves and progresses upward.
2.2 Wilting Despite Moist Soil: Damaged roots cannot absorb water, causing leaves to droop even when the soil is wet—a paradoxical sign of dehydration.
2.3 Stunted Growth: Energy is diverted to root repair, halting new leaf production. The plant enters a survival mode, conserving resources.
2.4 Foul Odor and Mushy Roots: Anaerobic conditions from waterlogged soil invite bacteria, producing a sour smell. Healthy white roots turn brown/black and disintegrate upon touch.
3.1 Overwatering: Rubber plants, adapted to well-draining tropical soils, suffocate when roots are deprived of oxygen. Excess water drowns root hairs, the primary sites of absorption.
3.2 Poor Drainage: Heavy or compacted soil traps water, creating a hostile environment. The plant’s roots cannot respire, leading to cell death.
3.3 Fungal Pathogens: Opportunistic fungi attack weakened roots. The plant’s natural defenses are overwhelmed, allowing infection to spread rapidly.
4.1 Immediate Root Inspection: Gently remove the plant from its pot. Healthy roots are firm and white; rotten roots must be pruned with sterilized shears to halt decay.
4.2 Soil Replacement: Discard contaminated soil and repot in fresh, well-draining mix (e.g., peat-perlite blend). The plant benefits from aeration and reduced pathogen load.
4.3 Adjust Watering Practices: Water only when the top 2 inches of soil are dry. The plant regains equilibrium as roots reestablish in a balanced moisture environment.
4.4 Fungicide Application: Treat remaining roots with a copper-based fungicide. This mimics the plant’s natural antifungal compounds, boosting resistance.
4.5 Prune Affected Foliage: Remove yellowed leaves to redirect energy to root regeneration. The plant’s metabolic load decreases, aiding recovery.
5.1 Proper Pot Selection: Use pots with drainage holes to mimic the plant’s natural habitat, preventing water stagnation.
5.2 Monitor Humidity: Rubber plants thrive in 40–60% humidity. Excess moisture in the air can exacerbate root rot risks.
5.3 Seasonal Adjustments: Reduce watering in winter when the plant’s growth slows, aligning with its dormant phase.
