I'm not clear if where you're planting them is a horizontal or vertical surface, but if you can get them to "stick" (if it's vertical), they should work very well. I've seen them growing in depressions in rock that seemed to have virtually no soil---but the more soil you have, the easier it will be to get them started. If these are small cracks, some of the smaller varities of hen & chicks would work better and probably look better too. I'd mix in a bunch of different varieties--there are some really cool, small "cobweb" ones. You might also consider mixing in several of the different ground cover type sedums and iceplants.

definately- they'll grow in the tinyst bit of soil... so will Dragon's Blood sedum, and most frost-safe succulents.

I've found they can be tricky to get started in areas w/virtually no soil. Sometimes, I've lost a couple and had to try 3 times but once you get one to "take" then they will do fine and spread well. So, just keep trying using as small a piece as you can separate off and eventually you'll get it. In one very small crevice...I just poked a stem (no roots) in between the rocks and, lo and behold, it grew to be a hen and had chicks all over the rocks. I misted the plant several times/day for a couple weeks...tedious but I had the time. Very cool...be patient and keep trying.

If it's an area that will get foot traffic though this might not be a good choice. The stems are very brittle and will break off easiliy. So, if a shoe brushes up against them going up your step...I think you could have trouble keeping them.

I am confident they will not tolerate foot traffic but are the easiest of plants and look perfect in sunny or part sunny crevaces. When they are doing well, some will send up flowering stems. I twist these individuals out immediately, since these individuals will die anyway after they bloom. I know some like the flowers,I don't.