I have a few indoor plants, mostly herbs. They are sitting on a window shelf I made so that they can get the sun that they require. I noticed this morning around the rim of the pot, which is your basic orange ceramic pot, a ring of something white, kind of chalky. Does anyone have any idea what this could be?
Certified GKH Gardening Expert
It is likely residue from your water. Minerals and chemicals in your water are left behind when the water evaporates, which can look like a chalky or powdery residue. It normally isn't a problem unless you have a water softener, which means that you will have water that is higher in salt and that salt will be building up in the soil of the plant, which will eventually harm it.
If you do have a water softer, I would recommend switching to filtered or bottled water or rain water for watering your houseplants.