Wow, lots of white powdery stuff on outside of terra cotta pots

hoorayfororganicFebruary 26, 2007

Is this calcium from my tapwater, or something?

Defnitly not mold, but is powdery and hard to get off the pot.

Thank you for reporting this comment. Undo
rhizo_1 (North AL) zone 7

It's likely a build-up of salts (from your water and/or your fertilizer) left on the outside of the container. Clay pots 'breathe' through micropores, and the salts are left behind as solids when the H20 evaporates.

A stiff or wire brush may help. If these are empty containers, you can soak them in a strong vinegar solution before taking a brush to them.

    Bookmark   February 26, 2007 at 12:22PM
Thank you for reporting this comment. Undo
Dibbit(z7b SC)

Rinse/scrub off as much as you can before you reuse the pots, especially inside the pot - if you stack them, what's on the outside will get to the inside of the lower pot. Too much salts, from fertilizer or anything, will burn plant roots. Try to cut down on your rate of fertilizing next summer - you are overdoing it a bit, it seems. And do water really strongly every so often, so the water runs freely out the bottoms of the pots, so you don't get a salt build-up on the top of the soil as the fertilizer(s) you used dissolved.

    Bookmark   February 26, 2007 at 3:58PM
Thank you for reporting this comment. Undo

im fertilizing with neptune's 1 time every 1-2 weeks. i have a feeling it's what's in the tapwater, because it's happening with somene else, on a different fertilizer regime (much less than I do)

    Bookmark   February 26, 2007 at 10:06PM
Thank you for reporting this comment. Undo

That is called "efflorescence" and is the dry deposits of calcium from the pots soil, or maybe even what the terra cotta pot is made from, as moisture moves from inside the pot to the outside, evaporation. Some people believe this adds character to their pots and leave it and many ancient pots have a lot of it and still grow plants quite well.
Because the deposits are calcium (mostly) and are alkaline a wash of a vinegar (acid) solution will remove it best.

Here is a link that might be useful: Efflorescence

    Bookmark   February 27, 2007 at 7:28AM
Thank you for reporting this comment. Undo
pablo_nh(z4/5 NH)

Just water hardness plating out there. I kind of like it on my teracotta pots- gives them a neat "old world aged" look, IMO. Sometimes it bunches up nasty, though.

    Bookmark   February 28, 2007 at 1:23PM
Thank you for reporting this comment. Undo
led_zep_rules(5 WI)

I also have a lot of white powdery stuff all over everything in my yard. It is called snow. But I guess that isn't what you mean. :-) Getting quite tired of it snowing all the time, although the shovelling is certainly good exercise. Have been reading my numerous gardening catalogs for solice.

Marcia, smart aleck

    Bookmark   March 1, 2007 at 12:57AM
Sign Up to comment
More Discussions
Double Post
Sorry for the double post, but I am still learning...
wayne_5 zone 6a Central Indiana
Re aphids - don't ants eat aphids?
I found what I think are aphids on my Salvia. Only...
Rock salt and asparagus
Someone told me he contols weeds in his asparagus patch...
Got tomatoes?
The organic Earthbox tomatoes have been coming in nicely...
Caterpillars - removing them the humane way
I have a small organic garden plot in my backyard (which...
© 2015 Houzz Inc. Houzz® The new way to design your home™