Efflorescence: White Powder On Pots And What It Means
Have you noticed that your older terra cotta or clay pots have crusty or powdery white deposits on them? You are definitely not alone! A ton of our members ask us what it is and if it’s harmful to their plants or them. The long and the short answer is: No. In fact, it is kind of a look that is becoming popular, and you will see some store bought pots with factory made “patina.”
First things first, let’s get into what the word efflorescence actually means. If you were to look it up in a dictionary, you would get more than one definition, and all pertaining to something blossoming. This is due to the root of the word being the Latin word for — I’m sure you can guess this — “flower.” In fact efflorescence can, amongst numerous definitions, quite literally mean a blossoming flower, but we’re here to talk about the chemical process.
The water that most people give their plants will have minerals, such as calcium, in it. Fertilizers, as we know, contain minerals as well. If there are more of these minerals in the soil than the plant can use, they can sit there and accumulate (which can burn the roots if not flushed) or they can go through pots if the pots are made of a porous material. Terra cotta and clay pots are permeable, which means that water and minerals can actually pass through them. As the water evaporates, it will take this surplus pf minerals with it to the outside of the pot, where they dry out and form this white powder/crust that we all know. You can think of it as this crust blooming, hence the word efflorescence.
Some people love this look, which is a hot trend right now, while others don’t. If you are in the not liking camp, don’t fret! You can remove it and keep the pots. Yes, it can be a bit difficult to remove, but far from impossible. All you need is to empty out the pot, give it a good soak in some water for about an hour, and use a stiff brush to remove the efflorescence.
Do you have more questions or are looking for more plant inspiration, information, or pictures? Want to show off your own plants or just talk with like-minded people from across the globe? Check out HPH on Facebook to join our global community of plant lovers! 🜄