It's been a long time since I've posted here. Anyway,

1) yucca arizonica - Tried 10 plants from seed about four years back, all killed.

2) yucca grandiflora - I have not tried it. Most plants originally offerd as Y. grandiflora years ago in the trade are now called Y. trec. canaculata. I think it was Mountain State Wholesale that introduced the seeds? PDN and Yucca Do I believe bought from them.

3) yucca periculosa - Tried one a few years back (may have been from Tim) - croaked

4) yucca angustissima - As Tim said they struggle here. I think mine are finally dead after 5-6 years in the ground.