I too have tried the lithodorum with so success and I just love the bright vibrant blue color. Will look up heliathemum for zone. Would be nice if I could get it to grow down the rocks by my pond. Thanks
this is a zone 5b. I doubt it will grow here, or rather survive. Drat. I really love the color. I have creeping phlox going down the rock now. Used to have several feet of it but the 'dwarf (NOT) mugho' overtook it. Now only have a few feet horizontally but it is draping nicely down to the falls bed. Need something on the other side which is more horizontal to compete with the weeds that grow in the rock. A total mess every year but I can't get down to the roots nor can I use anything chemical or otherwise to kill it out of fear it will go into the falls and thence into the pond killing my fish.I think I need to move all that rock this summer/spring, clean it out well, then plant something that grows well in rock and try to get it established before the darned weed seeds hit.
