Most of your questions should be answered to your satisfaction right here

In my opinion a deeper pot is better as it is easier to maintain persistent moisture. It dries out slower, which is important for seedlings. I like to use 3 or 4-inch deep square pots.

I would avoid pre-bagged "dirt" mixes. They generally have way too much peat and/ or compost, and not enough drainage. But feel free to try it and let us know about your experience.

IMHO, the best mix for Lithops consists of about 1 part poor garden soil + 3 parts drainage (fine gravel, pumice, perlite, some Turface, etc.). I have had very good success with that.

But remember that what works for me may not work for you. There are many variables (light, temperature, air, etc.). But once you figure out what works, Lithops are particularly easy to grow into adult plants.

x

Ou! Fantastic! Forget my being social for the next 2 weeks. [grin]

I figured that the pre-packaged 'dirt' would be far too rich and water retentive but then a part of me thought that maybe the seeds and plantlets needed the extra moisture and that the added nutrients aided cell division.

Thanks!

Yes they do need the added moisture but that does not mean the soil mix needs to be water retentive. The mix needs to be maintained "slightly' moist.

With a high "organic" mix, it holds so much water that aeration becomes compromised to a degree. A mix that is highly porous cannot hold the same volume of water, which is what you want. But that does not mean that a porous mix cannot be kept moist. It can, with more frequent watering, which also serves to flush out salts and replenish the oxygen. A porous mix will never be wet and gloppy no matter how much water is added - the excess just safely drains out.

I have also had success with vermiculite for seedlings. It is soft and fluffy. But it breaks down quickly into its clay components so the seedlings are best transplanted after 18 months or so into a more stable mix.

Right, one of the sites I was reading suggested misting them daily.
Vermiculite all by itself or added into a mix? I was under the impression that it's fairly absorbent (we have a big trash can full of it at work to clean up chemical spills), but I guess that could be a function of particle size.
Thanks for your input.

Yes, vermiculite into the mix. It is not really that absorbent, water seems to drain out of it fairly readily.