Root Rot on aloe vera
What's Happening
Root rot in Aloe vera develops when the rhizomatous root system remains saturated for 7+ days in poorly aerated soil. Unlike xerophytic cacti, Aloe vera retains fleshy water-storing roots that suffocate when oxygen levels drop below 2mg/L in waterlogged conditions. Anaerobic bacteria (Pythium, Fusarium) colonize compromised tissue, turning white firm roots into black mushy strands with characteristic sour/foul odor. The plant's thick leaves mask root decline until structural failure occurs—sudden leaf drooping despite moist soil indicates advanced rot. Oversized pots and moisture-retentive organic mixes accelerate decay by maintaining chronic soil moisture.
How to Fix It
- 1
Unpot and inspect immediately: Gently remove all soil; healthy roots are white/firm like potatoes, rotting roots are black/mushy/foul-smelling
- 2
Surgical removal: Trim ALL rotted tissue with alcohol-sterilized scissors until only firm white tissue remains; remove dead leaves at base
- 3
Sterilize remaining tissue: Soak roots in 3% hydrogen peroxide solution (1:1 with water) for 20 minutes to oxygenate and kill pathogens
- 4
Callus formation: Lay plant on dry paper towel in shade for 48-72 hours until cut surfaces form dry scab
- 5
Repot in dry gritty mix: Use fresh succulent soil (50% perlite minimum) in appropriately sized pot; roots should fill 60-80% of container; water only after 1 week
How to Prevent It
Use unglazed terracotta pots which wick excess moisture through porous walls. Water only when top 3 inches of soil are bone-dry—typically every 2-3 weeks indoors, longer in winter. Ensure soil contains 50%+ perlite or pumice for rapid drainage. Never use moisture-retentive peat-heavy mixes or oversized pots that retain excess soil moisture.