Root Rot on Monstera — How to Catch It Early and Save Your Plant
Monstera (Monstera deliciosa)
Symptoms
- mushy base
- black stem base
- root rot
- yellow leaves with wet soil
- wilting despite wet soil
- foul smell from soil
- black roots
- brown slimy roots
Causes
Chronic overwatering
The most common root of root rot. Roots need oxygen as well as water — when soil remains saturated for extended periods, the air pockets fill with water, roots are deprived of oxygen, and they begin to die. Dead root tissue then becomes colonized by anaerobic bacteria and Pythium or Phytophthora water molds, which spread the rot to adjacent healthy roots.
Poor drainage
A pot without drainage holes, soil that compacts and stays wet, or a pot that's too large for the plant (so the root zone is small relative to the soil volume) all create conditions where water cannot escape. The result is the same as overwatering even if you're technically not watering too often.
Cold temperatures combined with wet soil
Root metabolism slows dramatically in cold conditions. A Monstera in a cold room (below 60°F/15°C) processes water much more slowly than in warm conditions — soil that would dry in a week in summer might take three weeks in winter. Watering on the same schedule year-round without accounting for this creates winter root rot even in plants that are fine in summer.
Low light
Photosynthesis drives water use. A Monstera in low light transpires much less water, so soil dries slowly. Watering on summer-appropriate intervals while the plant is in a low-light position is a reliable path to root rot.
How to Fix It
- 1
Unpot the plant completely and gently shake or wash most of the soil from the roots. You need to be able to see the root system clearly. Do this over a trash can or outside.
- 2
Assess the damage. Healthy Monstera roots are white to tan and firm when pressed. Rotted roots are dark brown to black, soft, and may fall apart when touched. Note what percentage of the root system is affected — if more than 70% is rotted, plant survival is uncertain but possible with aggressive intervention.
- 3
Sterilize your scissors or pruning snips with rubbing alcohol before every cut, and work through the root mass removing anything discolored or mushy. Cut back to healthy white tissue even if this means removing a significant portion of roots.
- 4
Optionally apply a hydrogen peroxide solution (one part 3% hydrogen peroxide to three parts water) as a rinse over the remaining roots to kill any remaining anaerobic bacteria without harming healthy root tissue.
- 5
Monstera's thick cord-like roots callus more slowly than fine fibrous roots, so give the whole root mass a half-hour to an hour of open air before repotting — this also gives you a second look to confirm any roots you left in place are staying firm rather than starting to discolor.
- 6
Repot into fresh, chunky, well-draining mix — ideally with added perlite (25%) and orchid bark (25%). Choose a pot that's appropriately sized: only two to three inches larger in diameter than the remaining root ball. Do not use the same soil the rot developed in.
- 7
Place the repotted plant in bright indirect light and do not water for three to five days. Then water very lightly and gradually return to normal watering only once the plant shows signs of recovery (new growth or firm leaves).
- 8
If substantial roots were removed, consider cutting back some foliage proportionally — the reduced root system will struggle to support a full canopy while recovering.
Prevention
- Always use pots with drainage holes — no exceptions
- Let the top two inches of soil dry between waterings, verified by touch or a moisture meter
- Adjust watering frequency seasonally — much less in winter, when growth and water uptake both slow
- Use a well-draining mix with perlite and bark rather than dense, water-retaining standard potting soil
- Repot every one to two years to refresh soil that has compacted and begun retaining excess moisture
- Keep Monstera in temperatures above 60°F (15°C) to maintain healthy root metabolism
Quick Summary
| Plant | Monstera (Monstera deliciosa) |
|---|---|
| Category | Disease |
| Likely causes | Chronic overwatering, Poor drainage, Cold temperatures combined with wet soil, Low light |
| Fix steps | 8 steps — see above |