Bump...(Yucca brevifolia - from what I read, zones 6 to 10...where are you located? )

Speaking of joshua tree, has anyone grown from seed? I think I might have one.

I'm not sure what zone the Joshua trees grow in here in CA but those areas regularly get snow every winter, probably nights down into the 20sF or even high teens occasionally. But the days usually warm up to at least the 40s and usually the 50s, even in midwinter, so their native habitat isn't bitterly cold but much colder than the more coastal areas of CA. I hope that helps.

The winter minimum of an area is only a rough measure of climate. You need to be more specific of where you located. Eastern zone 6b climates are WET, WET, WET and that IS a factor too..., as are cold DAY temperatures. I lost a Yucca rostrada last Winter after two miserably cold and WET Winters. In the East, the wetness of our Winters is a definite limiting factor for essentially Western plants (that may relatively cold hardy in an ARID climate).

I am in the border of zone 7a/7b with dry winters and very hot humid summers, but in the summer there is not a large amount of rain. I am on the east, but it is not that bad.

I have yet to find a location where Joshua Trees can not grow. www.joshuatreeplantadoptions.com

Well. I'd guess they'd be a challenge mighty and strong in the Faroe Islands.