Adam: The only manfreda that I know of which is hardy north of Zone 7b is M. virginica, which has a wide range. I was in southern Minnesota last week and saw one that has grown well there for many years. Of the xMangave's, xM. 'Bloodspot' is the least hardy since A. macroacantha was a parent. Next is xM. 'Macha Mocha', which is a Zone 8 plant, using A. celsii. Our unreleased hybrids used A. salmiana v. ferox x Manfreda jalisciana, both solid Zone 7b plants. I would rate both Polianthes tuberosa and P. gemniflora also as Zone 7b plants, so we don't have any hybrids yet that will survive north of the Mason-Dixon line. Jon is slighter colder than we are, so he may have found some of his hybrids that can take Zone 7a temperatures. Adding A. polianthifolia to the mix is brilliant since it got no damage here this year at 9F. That being said, the work continues. 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 > >