I am with those that find it reliable- depending on species. In my mind I've always separated Polemonium into two classes, those that flower enthusiastically, seed abundantly, and are short lived (pretty much bloom themselves to death it seems, though likely fall into the short lived perennial category). My P. viscosum 'Blue Whirl' is like that. Then you have your longer lived ones (least they have been for me). I've had P. caeruleum 'Brise d' Anjou' for six or more years and reptens 'Touch of Class' for going on three now. I believe both of those last cultivars are sterile. The first gets mildew sometimes, but has always come thru it. PS. and before someone jumps on me saying I don't count since I live in "the temperate PNW".... the side of WA I live on is quite different from say Seattle- over here it is semi arid and snowy/cold in the winter. :-) CMK

I have 'Stairway to Heaven' and quite a few neighborhood cats with no fence and have never had a problem. (My poor birds and bird feeders on the other hand...) I've never heard that before!

Two winters ago I ordered some Polemoniums from a TN nursery. They sent me P. van-bruntiae, which I did not know at that point. I potted some up for a local native plant swap, and the auctioneer would not sell them because he said they were not Jacob's ladder! So, I brought them home and planted them. I am not sure if I still have them as there are so many Polemoniums in the area...I am not a neat gardener, and things "just grow" ...or not, as the case may be. Anyway, if I can identify them from the P. reptans when seeds start forming, maybe I can send you some.

Jacob's-ladder(Polemonium reptans var. reptans) Jacob's-ladder(Polemonium vanbruntiae)