Thanks, Arnold. I see from the Google results that these are rated zone 5-9, some rate them 5-8. Interestingly, Mobot had a page there too. Here are the cultural instructions: Use organically rich, very well-drained soil in full sun. Plant crowns 4-6 in deep. (Now this is in Missouri and perhaps this is to further protect them from freezing?) Winter mulch to protect young plants from early frosts. Mentions root rot if soil is not very well-drained. Says root rot may occur in poorly drained clay soils. Well, from what I have seen written, they 'sound' growable. I wonder what's up with Ken's? Cathy Craig President PBS Maritime zone 9b > > There was an extensive article in Gardens Illustrated a couple of years > ago and know they mentioned the ruiter hybrids. i will check to see if > I still have the issue and report back. > > Arnold