Thanks for the advice from all. Based on it, I've not yet decided on whether to proceed or not. Cetainly, the advertisement I received showing a magnificent stand of T. grandiflorum that was then followed by directions that they would grow and succeed here (San Diego) must be considered as a stretch of credibility. Use of a bog garden for some eastern species or of substantial irrigation for northern California natives might be possible. Neither will be easy to carry out in these in these days of drought in a dry region with thin shade. However, I'll let you know if this goes ahead. Andrew