I have a couple of big bunches. Mine are in a dry area that very rarely gets watered other than rain. I even have some in the front of the house which is our gravel driveway. I do leave the seed heads on in the fall. If any small ones appear in spots where they are not wanted, they are easy enough to pull. C

Brieen,
Could you tell us what the conditonas are like where you've planted them? what types are you growing?
I have a low growing small leaved kind with yellow flowers (russian yellow sedum I think its called)that is borderline invasive. I have another kind but I don't know what is called :'( They're both in full sun and sandy soil. I think if you can find a very sunny (even hot) place with very well drained soil they should do well. Another trick might be to place larger rocks beside them to keep the heat around them. They are definately hardy. My neighbor has clay soil and the samples I gave her died.
Hope that helps.