Mold in flower pots can appear due to mistakes made during plant care.
Most often, the problem is caused by frequent and abundant watering, too humid air, and mold appears if water stagnates in the pot.
First of all, you need to remove the top layer of soil, but you should do this carefully so as not to damage the roots.
After this, you can begin processing.
To do this, you need to dilute a teaspoon of citric acid in a glass of warm water. You need to water the soil in the flowerpot with this solution.
It wouldn't hurt to add a fungicide.
Next, it is necessary to carry out preventive measures so that this problem does not bother you again.
To do this, you need to follow the watering regime, place the flowers in places where there is a lot of light and no drafts.
You can also periodically use solutions based on citric acid or potassium permanganate.