If you water your plants with tap water that contains high levels of minerals (referred to as "hard water") you have probably noticed a white, cloudy or crusty discoloration on your plant pots. This discoloration is a buildup of minerals from the water. Although a few mineral deposits on the plant pot won't hurt your plant, it does detract from its beauty. Removing the deposits is relatively simple and can be accomplished in an afternoon.
Remove plants and soil from the pot. Rinse away soil residue with plain water.
Fill a bowl or bucket with equal parts white vinegar and water. Submerge the pot into the mixture and allow it to soak for one hour.
Remove the pot and scrub the deposit with an old toothbrush or kitchen cleaning pad. An old electric toothbrush works well as the circular motion lifts the residue free of the surface of the pot.
Soak the pot, if residue resists, in a bath of three parts vinegar to one part water or saturate a cloth with white vinegar, place it over the stubborn area, and allow it to sit for 15 minutes. Scrub to lift the mineral deposits from the pot.
Rinse the pot with water and wipe the surface with a soft cloth to remove any remaining residue.