Help with stained terra-cotta planters

Hi everyone -- I posted a thread to the "Clean and Clutter-Free" forum but I don't think that one gets as much traffic as this forum :)

May I ask you to take a look?

http://davesgarden.com/community/forums/t/1060692/

In short, I have two terra cotta pots (big ones) that have spent time outside and seem to have picked up mysterious persistent stains on the outside that I can't seem to get off. I'd love to restore the terra cotta to a nice uniform color again. The post on the other forum (link above) has a photo. Any help is greatly appreciated!!

Thank you!

Betsy

Betsy, I don't clean my Terra Cotta pots very often, but I have used a water and bleach blend when I have. Quite truthfully, I don't recall checking that the color of the Terra Cotta dried uniformly. But, I would start there. Someone else will probably come along with some more suggestions.

I posted to the other link. I don't clean mine very often either. I found a site that says to make a paste of baking soda and water.

Thanks Holly Ann -- I saw your posting on the original thread and I tried baking soda today. I'm not sure what the proper technique is -- just dab on the mixture lightly, press on a thick layer and let it sit, or scrub the pot with the mixture -- so I tried all of it. The result is that there is a *little* improvement. I didn't think it was going to work so I'm pleasantly surprised there's any change at all!

I'll post an "after" picture and keep working on it. I'm not sure what's happening -- whether the baking soda is somehow absorbing the surface stain, or whether the scrubbing is abrading it off -- but I'll take any improvement.

I'll try bleach on the tougher parts.

Thanks!!

Betsy

Betsy, You might give Oxyclean a go. Or even peroxide.

Am I the only one who thinks it looks like some kind of greasy spots? If so, maybe scrubbing it with some Dawn first would help. Or soaking it and then scrubbing it, because if something greasy has absorbed into the clay it might come right back out again.

I found your question interesting so I went googling. Found this:
http://www.howtocleanstuff.net/strategies/how-to-clean-terra-cotta-pots/

It appears clay absorbs salts & minerals from fertilizers, water & soil, therefore the stains. personally, I find it a lot of work to remove plant, clean & sanitize and put the plant back, especially since stains will eventually reappear. However, if you must have the neat appearance, you can do the following for future planters: get exterior flat paint matched to the exact color of your new terracotta pots. The paint will act as sealer and if pots are indoors, I doubt you will have to repaint again. If outdoor pots, you will have to retouch every two years or so, depending on weather.

I paint my outdoor pots white b/c I also like the "neat" look. however, there is maintenance as rains will lead to mold and paint will fall off in pieces every now and then. But I slap some paint right on top, and voila, pretty all over again! I have done this for many years. I must admit that I've come to realize this is way, way too much trouble, so I am gravitating towards the "lite" pots. They are easy to manuever, take paint well, and are more weather resistant.

For indoor plants I try to stay w/ glazed pots as they're zero maintenance.

hope this helps.

Interesting link vossner, I was going to suggest using vinegar and see that they've listed it as an alternative to using bleach :)

That is the link I posted to the other thread. Isn't it a great resource.

After all this I'm tempted to repot them into a plastic "lite" version. I love terra cotta but these things weigh a ton. I'd let them go to pot -- so to speak -- if they stayed outdoors, but they're indoors (for the foreseeable future) and I know the stains are going to bug me.

I agree that the stains look greasy. I've scrubbed them with 409 (no change) and now with baking soda (very tiny change) so I think they're permanent.

My next free Saturday or Sunday, I'll go get some replacement pots and move them over.

Thanks for all the ideas!