I would do it in the spring. This spring I planted some semps and sedums in my cinderblock garden in the holes. I used regular bagged potting soil and it worked much better than my soil/compost that I used in other holes. No shrinkage, less watering and the only weeds will be blown in. I hope they do o.k. for the winter in a raised bed and surrounded by concrete.

Kathy

Hi Traci. I've had the same problem--grass or clover growing among the semps and impossible to remove without separating most of the rosettes. But when that happens, you just plant the rosettes back together or, like dividing any perennial, relocate them to a more bare spot in your bed/garden. I guess the solution--especially with tough weeds like clover--is to keep on top of the weeding. I have found that if I weed regulary, the grass or clover does not get a chance to really settle in among the hens and chicks.

I wouldn't worry about the winter. One fall my wife left a bunch of semps sitting in a cardboard box with about an inch of soil still around the roots. They were out all winter (zone 1B) and were fine in the spring. They did have snow cover, however, which, I think, is all that these plants need to handle the winter.

Rand

Thanks for the advice. Its always so nice to get the opinion of other gardeners that have had the same problems.