I wanted to post a topic on yuccas that have been growing in Edmonton and ones that still have yet to take hold that I would love to try. Edmonton is natively a zone 3a area. The past 2 winters have been zone 5a ones and the ones before that over the past 10 years have been between 3b and 4b.
Yucca's that I have seen make it through Edmonton winters and ones that they sell are:
Yucca glauca, filamentosa, harrimaniae (just made it through first winter at local greenhouse with flying colors), flaccida. Those are the ones that I am sure of and I have seen a couple business' catch onto the idea of planting filamentosa (color gaurd). Cool enough its Chapters that has planted about 10 of them in front of their parking lot.
Yuccas that I am very eager to try and hopefully will get to some of next winter:
Yucca elata, thompsoniana, rostrata, faxoniana, bacatta, pallida, rigida, whipplei and brevifolia. The elata and faxoniana have been especially hardy in area's such as Colorado and Washington state where they see 4a/5a winters. I'm pretty sure Allen is the only other Edmontonian on this site, so Allen if you know any others that have made it through Edmonton winters then post it up.
Agaves have not be tried in Edmonton to my knowledge. I am going to try a parryi next winter and maybe havardiana or americana.
Nate
I haven't seen the yuccas at Chapters. Is it the store at South Edmonton Common?
I don't know of any other yuccas that are growing outside here. Salibury Greenhouses has several mislabeled yuccas in their tropical plants. When I asked about Agaves nobody knew what they were. They may have over 1,000 sq Ft of tropicals but they only had 2 varieties of Bananas, 2 or 3 yuccas and maybe 30 unlabelled cacti.
I am looking at trying A. parryi myself and maybe A. toumeyana v. bella if I can find one.
Allen
You don't have to be crazy to grow palms in Alberta..... But it helps
Ya it was in south common, they were covered by 3 feet of snow but I think they're starting to appear now. I didn't get a good look last time I passed by but I will check it out soon and tell you how they did in their first winter.