Symptom · 1 possible cause
White fuzz or threads on the medium surface
Appears on moist, organic-rich topsoil or mulch; plant healthy..
- Also called
- white fuzz on soil
- mould on soil
- white web on top of soil
- white mycelium in pot
Likely causes, most likely first
Ranked for this sign on its own. Your stage, medium and readings change the order, so run the checker for your plant.
LikelyHarmless white fungus (mycelium) on organic medium
Fix: Usually beneficial or harmless decomposers on mulch and organic matter. Let the surface dry more between waterings and improve airflow; scrape it off if it bothers you.
Recovery: Plant stays healthy; fuzz recedes as the surface dries.
How to confirm it
- Lift the pot and check moisture at depth. Lift the pot right after a full watering to learn its wet weight, then lift before each watering. Water when it is clearly lighter (about half the added water gone). Push a finger or a moisture probe 5 cm (2 in) down. Heavy for 3-4+ days with droop: overwatering. Very light with limp papery leaves: thirst.
Look for
Cottony white threads on the soil or mulch surface, not on the plant..
The full guide: What is the white fuzz on top of my soil?
Guidance, not a guarantee. The checker weighs common causes against what you tell it; confirm with the tests before you treat, change one thing at a time and watch the new growth.
