⚠ CriticalPothos Root Rot — Pythium & Phytophthora in Waterlogged Substrate
Commonly affects: Epipremnum aureum — all Pothos cultivars
The plant wilts even when the substrate is moist, leaves yellow and collapse, and a foul odour rises from the pot when watered. Removing the plant from the substrate reveals brown-black, slimy roots that fall apart on handling. Healthy Pothos roots are white to cream and firm. Root rot in Pothos is caused by water moulds (Pythium spp., Phytophthora spp.) that colonise waterlogged root zones, breaking down root tissue and cutting off water and nutrient uptake entirely. The plant effectively dies of thirst while sitting in water.
Potential Causes
- 1Chronic overwatering maintaining the substrate in a saturated state for days at a time
- 2Heavy, peat-based substrates with no drainage amendment that compact over time and trap water
- 3Pots without drainage holes, or drainage holes blocked by compacted soil or pot saucers
- 4Cold root zone temperatures below 15°C slowing root respiration and increasing susceptibility to pathogen colonisation
Solution Steps
- 1Remove the plant from its pot immediately. Shake off all substrate from the roots and rinse with clean water.
- 2Trim every brown, black, or mushy root back to firm white tissue using sterile scissors. Sterilise scissors between cuts with isopropyl alcohol.
- 3Dust cut root ends with powdered cinnamon or sulphur as a natural antifungal barrier.
- 4Allow the trimmed root ball to air-dry for 30-60 minutes before repotting.
- 5Repot into a completely fresh, well-draining substrate. Do not reuse the old mix — it contains the pathogen.
- 6Water sparingly for the first 3-4 weeks — the reduced root system cannot absorb large volumes. Resume normal watering only once new white root tips are visible.
Prevention Tip
A substrate of 50% potting mix and 50% perlite almost entirely prevents Pothos root rot by ensuring drainage and air pockets remain even after thorough watering.
