Administered in the right dosage, fertilizers are necessary to maintain healthy houseplants. Plants can't thrive without salt nutrients, but fertilizers, especially those with high salt indexes, can be harsh on the clay pots plants live in. Salt stains form a residue that sticks to porous clay pots after water evaporates from fertilized soil. Since it's difficult to avoid salts without hurting your plant, the best option is to clean the clay pot to remove salt stains. Clean pots like a pro, using an advanced treatment such as a light duty cement cleaner on the most stubborn stains, while giving the pot's color more depth and brightness.
Spray and/or wipe the pot down with water using a sponge.
Apply cleaner directly to the wet pot surface using a sponge or brush, wearing gloves. Begin from the bottom, working your way up using scrubbing motions.
Let cleaner stand on the pot for three to five minutes.
Reapply the cleaner in the same manner as in Step 2.
Rinse immediately (no need to let stand) with water to remove the cleaner, either by spraying the pot down while scrubbing, or wiping it down with a sponge soaked in fresh water.