It looks like we have a clear winner on hardiness........ Y. linearifolia is 'mint' while Y. carnerosana 'Mexican form' is dead? Low temp was -6.5F (-21.4C) with many, many, many other cold days/nights. Both moisture protected in the 'tubes'.

Hi Tim,
that's a very interesting hardiness trial, I'm very impressed whith your Yucca linearifolia, this one looks almost fine !

Hi Tim,

Y. linearifolia is the better Y. rostrata and more hardy than carnerosana.

Hi Tim,

the linearifolia looks good - on of my most fav yucca! You`d better try Y. faxoniana, i have planted out one 5 years ago, grows each year better and better

I join your opinions about Carnerosana's hardiness. Tried several times in my yard, it has never survived more than two or three winters.
What are the keys of differences between Carnerosana Vs Faxoniana ?

Franck.

nice photo showing the difference......I agree the mexican form of Y. carnerosana looks like a robust form of Y. filifera.