Jim: Back in the 1980's, when we were in the midst of global cooling, we tried quite a few Polianthes tuberosa selections. They were fine if winter temps. didn't get much below 5 degrees F. If the temps dropped to 0 F, we would loose 100% of the green leaf ones. Interestingly, one of the creamy edged forms (from Jim) made it through the 0F winters and still is doing fine. I'm not sure if this is a hardier genotype or if it simply doesn't have the level of virus of the commonly grown green-leaf types. We have only been growing P. gemniflora since 2003, but it's been fine since then, down to 8 degrees F. The P. x bundrantii hybrids were disappointingly weak, after winters of 8 degrees F. P. bifida, P. howardii, and P. platyphylla were not hardy below 10 degrees F. in our trials. The xMangave (Manfreda x agave) was grown from seed collected in the wild of Mexico by Carl Schoenfeld of Yucca Do. I went to YD in 2003 to witness the first flowering of the hybrid, which, to my knowledge is only the 2nd bi-generic hybrid from the wild. FYI, there were 2 hybrid seedlings, but the second one has not been released. We are still looking for someone to publish the hybrid name. For the variegated plant nuts out there, we have xMangave 'Macha Mocha' with a wide creamy border and a wide creamy center.Keep in mind that since bi-generic hybrids upset taxonomists view of the world order, there is already a renewed push to combine agave and manfreda in to the same genus. This is more curious since phylogeny work shows that agaves are actually most closely related to hostas....how about breeding possibilities for xHostaves? I hope this helps. Tony Avent Plant Delights Nursery @ Juniper Level Botanic Garden 9241 Sauls Road Raleigh, North Carolina 27603 USA Minimum Winter Temps 0-5 F Maximum Summer Temps 95-105F USDA Hardiness Zone 7b email tony@plantdelights.com website http://www.plantdelights.com/ phone 919 772-4794 fax 919 772-4752 "I consider every plant hardy until I have killed it myself...at least three times" - Avent James Waddick wrote: > Dear Dennis, Steve and all; > > I think subject of Manfreda x Polianthes hybrids is a > fascinating new topic, but it got me thinking. > > I grow three species of Polianthes and always bring them in > for winter, but how hardy are they outdoors? I did a quick Google > and came up with Zone 6 - 7 - 8 and 9 ! just for P. tuberosa, the > most common species. Surely someone in PBS grows them out doors with > success. I'd sure like to hear what species you grow outdoors and how > hardy they have been. > > Likewise does anyone grow any of the other Manfreda species > in cooler climates? I always assumed they were too tender. And M > virginica has the widest range (and tolerance?). > > So who is growing which species and where. > > Just FYI you can see some other Polianthes sp at > http://www.yuccado.com/ > > The author of the article on the hybrids suggests that these > crosses have been made before. Anyone grow any of these or are they > available commercially ? > > I did come across the "mangave" a possible "hybrid between > Manfreda variegata and Agave celsii [A. mitis] " > > Thanks for bringing up this topic. Jim W. >