Running dog,
I have used cheap potting soil in place of peat moss. Because you are using sand with your mix I do not see a problem. The ratios you mention will likely produce a rustic mix that will pit and loose surface materials in time. But may not be much different than what peat moss look would be.
The mix I used was 1Cement:1 1/2 Sand:1 1/2 potting soil
What are you making?
Dena

lol - haven't decided. Just thinking that it might look interesting.

Earth can be difficult because it can contains fines, organics, and other materials that interfere with proper curing.
Even peat moss over time will degrade and your pot will becoming increasingly weaker as time passes.

I recommend you make your pots in TWO layers. Make the inner layer of a good strong concrete recipe, then apply your earth/peat recipes to the outside of that. There is no need to wait, you can apply your decorative earth layer immediately to your concrete layer. If you do wait make sure your pot is good and wet before applying the next layer and using a good concrete glue between the layers will help insure a good bond between materials.
Cure properly and over time as your outer layer decomposes adding that great aged look your pot itself will remain strong.

Using the layered method you can go completely nuts with the decorative layer because a strong cure is not necessary for a strong pot.

Thanks for that information :)

I covered a trough in a peat recipe adding old cooked spagetti and crushed dry elm leaves and a pinch of plant fertilizer.
I left it outside in the rain and the spaget was gone in a week leaving a very cool and rustic wormy pattern. This pot is now growing some sort of green stuff, not moss, in the holes left by the spagetti and it looks cool.
Or did look cool, it's frozen to the ground right now so I'm not sure it's going make it through the winter.

Here is a light green shell that will be covered with a soft vermiculite and peat recipe. That will then be shaped with a brush until the green shows through in places. The corners are broken away to allow the peat recipe to be built up in that area in hopefully a pleasing shape.
Attach a carved green stand to the base and it should be a fine bowl.I can use a soft organic finish because this shell although made with cryogenic perlite and quite light weight is darned strong.

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Here is the reverse. The picture doesn't do this justice. There are sparkles and pink hues not visible. It's a pure oyster shell recipe and quite pretty in the sun and really nice with a gloss sealer.

This is the outside made first and so porious you could use it as a sieve. But I will line it with a thin water proof white or blue concrete that will also extend through the bottom to form the pedestal base. There are tons of stuff that can be done using layers.

Yes this does take a bit longer but not that much. You are working with smaller batches and it allows materials that on theie own just don't work.

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"I left it outside in the rain and the spaget was gone in a week leaving a very cool and rustic wormy pattern. This pot is now growing some sort of green stuff, not moss, in the holes left by the spagetti and it looks cool."

I think I mentioned on here already about making a sloppy dough with flour and water, and painting that into the inside of the mould. That has the same effect, causing mould to form. I've tried this only with plaster, and in the case of the plaster the flour also reacted in some way with the plaster (perhaps because it was self-raising flour, so it contained bicarb) and pitted the surface of the plaster in a very interesting way.