Cleaning flower pots is a chore all gardeners must do at one time or another. There are several ways to clean pots and some depend on what you are trying to clean. Most times gardeners clean the pots so fungi and bacteria are not passed on to new plants. Other times, it's just to make them look nicer. You will find it's not very difficult to have new looking pots every season and most supplies you need are already in your home.
Brush off any dirt or debris that is on the pot. Use a stiff brush for clay and a plastic scrubber for plastic. Soak the pots in nine parts hot water and one part bleach for an hour. Rinse the pots off with warm water.
Wash the pots with a mild dish washing soap and water. You may need to scrub them a little more. Then soak clay pots in clean water for another hour; plastic pots can just be rinsed.
Allow the pots to dry completely and they should be ready to use.
Disinfect small or medium sized clay pots if you know for sure there was a diseased plant in them before by placing them in your oven at 220 degrees for an hour. Allow the pots to cool in the oven to room temperature before you handle them.
Scrub salt build up off of pots by making a baking soda paste with a little water and scrub clay pots with a fine steel wool, and plastic pots with a plastic scrubber.