I want to stop moisture wicking through a terracotta plant pot.

What can I paint inside to seal it?
Would marine varnish work?
cheap easy options please.

I have done this. Use 'concrete sealer' or 'marine sealer' - something made to be wet.

I'm only putting a big spider plant in it but I worry a bit about chemicals leaching into the plant soil.

Any thoughts?

Can I get away with marine varnish?

Thanks for ideas

Normally there are no chemicals for you to worry about. Are you thinking about chemicals inside the pot leaching out or chemicals outside the pot leaching in?

I'm thinking of possible chemicals from the sealant (painted inside the terracotta pot) causing issues with the plant growing in it.

We used to sell a sealant made for ponds, so it was safe for fish and plants; you might look for something like that.

Hortica said: We used to sell a sealant made for ponds, so it was safe for fish and plants; you might look for something like that.

That black stuff. That's what I was thinking about. I sealed a water bowl I had goldfish in. They didn't seem to mind.

I think your marine varnish would be safe and effective. Assuming you mean a spar varnish and not a product intended for use below the water line.

Lucy68 said: That black stuff. That's what I was thinking about. I sealed a water bowl I had goldfish in. They didn't seem to mind.

No, this stuff was light in color. There may be more than two versions.

Another easy suggestion I've seen online .... PVA glue diluted with water. I know this works for sealing plaster, but can feel tacky when damp. .... JUST ANSWERED MY OWN QUESTION, DRIED PVA DISSOLVES, SO NO GOOD BY ITSELF

Your simple cheap ideas & thoughts are very welcome!

I bought something called pot sealer in a spray bottle in a garden center, once. Can't remember any personal experiemce with it, how well it worked etc

Maybe you just need a plastic pot? The brilliance of the clay pot is the porousness/breathability. I think it would be much less expense to buy a plastic pot vs. some product meant to waterproof something.

Or just put a plastic pot inside the terracotta one.

Is it a "special" terracotta pot?

I have a huge spider plant in a terra cotta pot that is still thriving after almost 50 years and has gone through several repottings. Wondering why you would want to seal your pot as breathable terra cotta is a great choice for a plant like a spider that has tuberous roots and doesn't like wet feet.

I have not used this yet. Bought at a garden store.