Mold on "4 Season Cactus" Soil: Wrong Soil, Too Wet

Cactus Soil Shouldn't Grow Mold

White fuzzy and green mold indicate soil stays wet and is high in organic matter—wrong for cacti. Cactus mix should be sandy, low-humus, and dry completely between waterings.

Immediate Steps

1. Scrape off surface mold and loose soil.
2. Let soil dry completely to bottom before watering.
3. Ensure direct sun—light inhibits mold.
4. If soil is wrong, repot in proper cactus mix (but wait until April).

Mold won't kill the plant directly, but wet soil will rot roots.