Mushrooms in Houseplants Signal Overwatering

Yellow mushrooms growing in a Christmas cactus pot indicate the potting soil is staying too wet, allowing fungi to decompose organic matter. The mushrooms themselves don't harm the plant, but the conditions that favor them—constant moisture—lead to root rot.

Repot the cactus in fresh, well-draining potting mix. Water only when the top inch of soil feels dry. Going forward, check moisture with your finger before watering. The mushrooms will disappear once the soil dries out.