What is yellowish crust?

Yellowish-brown powdery crust on your plant's soil surface can develop as a result of peat mold. Fungicides typically aren't very effective against this type of mold, however, it's not harmful to your plant— just more of an eyesore.

Signs

• A crust on top of the soil, ranging in color from yellowy-orange to brownish, and often powdery in consistency

• There may also be white mold on the soil surface

• Sometimes there may be a 'damp' odor surrounding the affected plant

Possible causes

It may be an indication that the soil is staying too moist for long periods of time. So it's important not to overwater your plants. The mold itself isn't usually harmful, but overwatering can cause a lot of damage.

This type of mold only develops in decaying organic material, like peat, which is where it gets its name. You don't need to worry about it spreading onto your living plants.