Baking and cinnamon: old‑fashioned solutions tackling mould in potted plants

We could inadvertently bring soil infected with fungi and microorganisms into our home, for instance, if we use soil collected independently from a meadow. Sometimes we could unknowingly purchase “infected” soil from a store. However, even in such situations, there's a straightforward preventive measure.

Drying potting soil is a simple, effective trick our grandmothers used to protect against planting flowers in mouldy soil. What do we need to do? If there's a white coating on the soil lumps, dispose of those parts. Spread the remaining soil on a sheet and place it in an oven heated to roughly 90 degrees Celsius for about 30 minutes.

Don't cover the soil when in the oven; it should evaporate freely while baking. Stir the soil several times during the process to ensure even drying. This method sterilises the soil, helping eliminate fungi, mould, and microorganisms or harmful insects. Once the soil has cooled down, we can use it.

Cinnamon can be very effective against fungi in pots. It's worth using if mould appears in the soil of an already planted pot. Simply collect some soil where the characteristic white coating is observed, and add a teaspoon of this spice. For enhanced effect, it can be mixed with the top layer of the soil.

However, not all white coatings on the surface are mould. Sometimes we're dealing with a lime deposit caused by watering plants with hard water. While not harmful to plants, it can be aesthetically displeasing, hence it's better to use boiled or filtered water.