Dear All; Now that Dennis has open this 'box', I'll add 2 cents. I grow P. incarnata here with little trouble and I know where it has been for years longer than mine. I have never tried P. lutea, but it is native not too far south of me in Missouri. I have tried and lost the hybrid 'Incense' ( a cross of P. incarnata x P. circinnatum( A South American species)). I have seen it grown successfully near here, but suspect it is very "on the edge". * I must note Elizabeth Peters of Grassy Knoll Exotic Plants (http://www.gkexoticplants.com/) She is very generous in sharing info and offers a number sibling crosses to 'Incense' such as 'Blue Velvet', ' Temptations' and others. She has also suggested other potentially hardy species such as P. gracilis (out of stock - does any one have seeds or plants to share?) P. incarnata has such intense and unique flowers it is well worth growing although it can be quite a pest in sending up shoots all over the place. Siting is important. I wish more people in colder climate would have some interest in developing hardier hybrids as obviously these are possible. Dennis this is a good new topic here. Thanks Jim W. * Incidentally Elizabeth thinks that all commercial stocks of 'Incense' are infected with a virus that cause it grow less vigorously and mean less hardiness without actually killing the plants. New hybrids are virus free and some tetraploids may be even MORE vigorous and hardy. My kind of plants. -- Dr. James W. Waddick 8871 NW Brostrom Rd. Kansas City Missouri 64152-2711 USA Ph. 816-746-1949 Zone 5 Record low -23F Summer 100F +