Alas, those I am growing were collected during a roadside stop in February near Billings, Montana. I suspect they will throw the typical cream blossoms, but those will be welcome regardless.
zone 4a/5a, Missoula, Montana
Your no doubt right about the color. Have you ever tried to move a Y. glauca in from the wild? I have on several occasions dug smaller specimens with very good results. They have a very long tap root but you don't necessarily need to get all of it. A foot or two of it will normally be enough, especially if you dig it in early spring. The roots you leave in the ground will often resprout. I have even had the crown rot off of one. It come back from the dead by the end of the summer and is a fine specimen now. I'm wondering if a person could take a root cutting form secondary lateral roots and use them for propagation.
From the High Desert Steppe
of the Great Basin and the Eastern
Escarpment of the Sierra Nevada Range
Located in Reno/Sparks,NV zone 6-7http://www.flickr.com/photos/sierrarainshadow/
John P Weiser
So John, did the roots left sprout in multiplicity, or just one sprout per group of roots?
Was there a difference between dug plants and the one who's crown rotted?
Rick Rodich zone 4a. Annual precipitation ~24 inches
near Minneapolis, Minnesota, USA
Some times there are a couple of new crowns not very far apart. I imagine were a few of the larger roots were severed. The rotted plant came back as two crowns right were it had rotted, so I think laten buds on the good portion of the tap root took over.
The only advice I have ever heard regarding root physiology for cuttings is a size consideration. I have never heard it mentioned, for example, that the actual taproot might be better for cuttings than the laterals, given equal girth. Purely based on this, it would seem that latteral root cutting propagation of at least this species of yucca would be successful.
I would have thought that someone would have tried it by now, though. Maybe someone out there has...?
I think excavating a plant can be done without lasting damage. I've certainly done so with another species of yucca--Y. baccata, I think--and it responded as John suggested: I now have two very large specimens in separate parts of the garden.
By the way, Michael, that is a drop-dead gorgeous avatar photo. I don't want to veer from the Yucca topic too much, but what is it?
It is Castilleja scabrida, taken on 28 April last year in a canyon that is tributary to the Escalante River between Boulder and Escalante, Utah. I've not (yet!) attempted to grow it, because I lack hectares of sandstone.