Leaving it out in the rain would be good. It will keep it damp so it will cure slowly and make it nice and strong.
Cindy

I would think it needs to setup for 24 hours (give or take) before sticking it out in the rain. But I'm not that knowledgeable about tufa. Only made a couple things. Just wouldn't want to see it get washed away in that much rain.

My 2 cents worth of advice.

Joyce

I know that concrete cures happily underwater, in fact it cures better that way, but wasn't sure about this porous mix. I'm also a little worried that some torrential downpour might come along and wash it into a pile of mud! Hopefully the forecast of light rain, at least overnight, is correct.

Well, several torrential downpours later ... the trough is mostly still there. A few tiny bits seem to have been washed or knocked off but it now seems quite robust. Temperatures outside are only about 50F so it isn't ready to play with yet. Still raining!

Both tufa and concrete should be "set" enough so you can't easily dent it with a fingernail before you put it under Mother Nature's firehose. If it's still soft, it could well wash away, or at least erode.

Sue

It survived our unusual weather. 48 hours on and here it is. Not much by the standards here, but I'm proud of it :)

{{gwi:74990}}

It looks great, all the rain will help to get it ready to be planted in by continually washing it off. Good job.
Cindy

There's nothing wrong with that -- looks good to me. Don't forget to put some drainage holes in it when you are ready to plant. I have found that "semi-porous" or not, they need those holes!

You should usually wrap your item up in plastic for 24-36 hours to get an initial set, before you try moving, texturizing the surface, and otherwise monkeying around with it or it will break (ask me how I know this :) ).

Keep pluggin along -- you are off to a good start.

It has drainage holes dowelled through. It also has small feet at the corners which aren't very visible, just to raise the drainage holes off the ground.

I'm so pleased I made another one, using a slightly different mix with perlite instead of vermiculite. Once I decide which I like best I'll be ready for the big trough that I need :)

Groovy!

Wecome to all the fun and creativity that playing in the mud bestows on us all!

I can tell you are gonna do jus' fine!! Great planter!

Marly