WHY DOES THIS HAPPEN
The most likely cause of brown spots beginning to appear on your Pilea is having received too much water. If it begins to show signs of spotting, you can give the soil a quick check to see if this is the case. If the soil is still moist, then you should try to avoid watering again until it has had a chance to dry out a bit — just snooze your watering notifications in Planta.
However, brown spots can also be the result of overexposure to the sun, or by overfertilizing/ using the wrong type of fertilizer.
If you think your Pilea may have gotten too much sun, you should move it to a shadier location in order to give it some time to recover.
Or, if it seems that the problem could be overfertilizing, hold off adding any more fertilizer for the time being. You should also check that the fertilizer you are using is definitely suitable for Pilea peperomioides. Receiving too much fertilizer, or using too harsh a fertilizer for your plant can be harmful as it can burn the roots of the plant, preventing it from being able to take up nutrients and water. It’s always better to lean more towards underfertilizing than overfertilizing, as it’s much easier to treat an underfertilized plant.
Brown spots and browning of the edges of leaves
Leaves may also begin to fall off
You should also check to see if there are any pests on your Pilea, as brown spots can sometimes instead be caused by pests