What I did was cram some soil into the crevices in the rocks, poked the sedum plugs into them, topped with more soil and watered it in. Kept applying soil and watering it in until it stopped washing away. Sometimes I'd need to pack some smaller stones in to help hold the soil.

hope that helps :) I'll get a pic in a little bit to show mine.

Kd

bunkfree_4a_canada I

Didn't realize it was so simple. How deep is the soil... I heard it should be like 2ft deep

No, it doesn't need to be so deep. Could be grown in pots - much shallower.

In case it matters I live in zone 4b

would it work to pot sedum in succulent soil (ingredient- peat moss, compost, sand, limestone, and perlite or turface or would it be good to mix with the earth/ground where I plant sedum?

Do both, Heather, the plants won't mind, but remember, unless you're in the southern hemisphere you're not going to see growth on them until next year. Still, it gets them acquainted with their new home, and the roots will have time to settle. As they're going in the ground, presumably in an area of good drainage, they don't need it as porous as you'd have it in a pot. Many times Sedums can just go right into the ground, provided that ground is somewhat loamy, but it usually doesn't hurt to improve the soil some.

what mix of soil? I can order gritty mix (ingredient- Bonsai Block®,
Monto Clay® and Pine Bark Fines.) or turface, at home I have a cactus
succulent mix (ingredient-compost, peat moss, perlite, limestone),
perlite, vermaculite..would a combination of these be a good mix of
soil? What soil would be good to pot them in...and what would be good to add to the soil in going in the ground?

Use the cheap stuff for the ground, save the bonsai mix for your pots. Any mix that's porous would, I guess, be good for pots, but as I grow all my Sedums in the ground maybe you want to wait for someone else to answer.