White mold on houseplant soil is usually saprophytic fungus feeding on organic matter in damp potting mix. It is often harmless to the plant, but it is a sign the soil surface is staying too wet.
Quick Answer
Remove white mold from soil by scraping off the top layer, improving airflow, letting the soil surface dry, reducing watering, and removing dead leaves from the pot.
Why It Appears
Mold likes moisture, still air, low light, and decaying organic matter. Overwatering and dense soil make it worse.
Is It Dangerous?
Most white surface mold is not directly dangerous to healthy plants. But the conditions that create it can lead to fungus gnats, root stress, and overwatering problems.
How to Fix It
Scrape off the moldy top layer. Let the top inch of soil dry before watering. Move the plant into better light if appropriate. Increase airflow and remove fallen leaves from the pot.
If gnats are also present, read [how to get rid of fungus gnats](/journal/how-to-get-rid-of-fungus-gnats).
Bottom Line
White soil mold is usually a warning, not a catastrophe. Dry the surface, clean the pot, and adjust watering before the problem invites pests.