Saprophytic Surface Mould (Usually Harmless)
White, fuzzy, cottony patches on the top of the growing medium are almost always saprophytic fungi feeding on dead organic matter (compost, husks, mulch). They are not plant pathogens and are not root rot. They show up when the surface stays consistently damp with little airflow. Scrape off, let the surface dry between waterings, and add airflow under the canopy.
What usually causes it
- Surface of the medium kept consistently wet
- Poor airflow at substrate level
- High organic content in soil or top-dressing
- Cool, low-light room conditions
Related product categories
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