How to Get That White Coating Off Your Terracotta Pots
When deciding which type of container is best for growing your plants, you’ve probably at least considered traditional unglazed terracotta pots. They have long been a home gardening staple, and for good reason: they are relatively inexpensive, they can be reused, and they are porous, allowing for air and water exchange.
But they also tend to form white spots on the outside of the pot. And while some people consider it part of their rustic charm, others find the tape unsightly and want to get rid of it. Either way, here are a few ways to remove the white buildup on the inside and outside of terracotta pots.
What is the white sediment on the outside of terracotta pots?
The white film or crust that forms on the outside (or inside) of clay terracotta pots are soluble salts. Hard water (which includes most tap water) contains salts and minerals. When you use it to water your plants and it eventually evaporates, it leaves behind these salts and minerals as a white residue – sort of like what happens on shower heads.
Meanwhile, if you have softened your tap water, you may still see that white coating on the outside of your terracotta pots. But in this case, it is probably caused by the application of fertilizers containing minerals to the soil. Because these clay pots are porous, minerals from the soil seep through the pot and may show up as residue.
How to clean terracotta pots from white plaque
If you really want to clean your pot thoroughly, it’s best to do it when it’s empty. Otherwise, depending on the condition of the plant, you may want to consider removing it from the pot for the cleaning process, especially since there are probably soluble salts inside as well.
Here are three common methods:
Vinegar
Make a solution of one part vinegar to 20 parts water. Soak the pots in the solution for about 30 minutes, then wipe off any white spots and residue . Rinse thoroughly with clean water, then let the pot dry.
Bleach
Prepare a solution of one part bleach to nine parts water and use it to clean the inside and outside of the pot. Rinse thoroughly with clean water, then let the pot dry.
Baking soda
Make a paste of baking soda and water and use it as a spot treatment to remove the white buildup.
Is it possible to leave a white coating on the pan?
While it’s always a good idea to remove the white film that forms on the inside of a terracotta pot (to prevent soluble salts from getting into the soil), leaving residue on the outside of the pot is usually fine. According to an article in Horticulture Magazine, “salts on the outside of the pot will not harm the plant.”