How to Neutralize Mold in Soil

Break up the soil with a gardening trowel or similar tool. This allows for greater water penetration and prevents moisture from accumulating at the top of the soil. Better water distribution in the soil beneath the surface prevents standing surface water contributing to fungal growth.

Expose your plant to ample sunlight. For houseplants, move the plant to a more well-lit windowsill. For outdoor plants, uproot the plant and move it to a sunnier location entirely. A lack of sunlight inhibits moisture evaporation, which potentially leads to mold problems.

Provide your plants with adequate air circulation. In addition to sunlight, all plants need proper air circulation. If you have many plants crowded together, or if you have houseplants in a room with limited air circulation, move them to an airier location.

Examine your plant leaves for other fungal diseases, such as powdery or downy mildew. These similarly white fungi primarily grow on leaves in chalky patches, but can spread to the soil if not managed. If you find powdery or downy mildew, prune the affected leaves and spray your plant weekly with an oil-based fungicide.

Water your plant regularly. Just as too much water leads to mold growth, not enough water can weaken the plant, leaving it vulnerable to fungi and plant diseases. The watering frequency depends on the type of plant and the amount of natural moisture in the air. Never let your plants suffer prolonged dryness.

Replace the soil. If all else fails or if patches of mold continue recurring despite your best efforts, you may need to simply scoop out the soil completely and replace it with new soil from your local home or gardening store.