Thanks for getting the joke, gardengal. It was a pleasure to demonstrate that I can troll my own response better than anyone else can. Of course Sequoiadendron is much hardier. But the problem is it is also much more suspectible to disease caused by our muggy summer conditions. If you were to blend the Mason-Dixon line with the new USDA zn 6/zn 7 line, you would get an approximation of the east coast boundary between areas where Sequoia (coastal redwood) and Sequoiadendron could be grown on the east coast. Sequoia south of it, obviously, and Sequoiadendron north of it. Even north of the Mason-Dixon line, the several Sequoiadendron at zn 7 Planting Fields arboretum looked pretty bad. OTOH I'm pretty sure I saw one at a garden in Carlisle, PA, zn 6, that looked reasonably well. Nights there are probably a wee bit cooler, and I suspect you could grow them all the way down to Georgia on the highest mountain tops that stay in the 50s at night. Go too far north though, even zn 7 is still going to be too cold for Sequoias. One supposes that the Polly Hill arboretum, for example, has tried them and they aren't on the plant list for a reason. (still meaning to email them about strange tales of a monkey puzzle that dies back in some years yet persists)

That's interesting Fotis. Certaintly, my climate is probably somewhat cooler on average than yours in winter: http://www.sercc.com/cgi-bin/sercc/cliMAIN.pl?de6410 and definitely moister year round, but maybe only slightly more so in winter. Or maybe not at all: there are places in Greece that are quite moist and similar in some respects to some interior valleys of coastal Northern California, albeit markedly moister and more humid in summer. Are you similar to this place? (sorry about our antiquated temp. scale and the need for conversion!) That's kind of like Ukiah, CA with slightly cooler winters and somewhat wetter summers. Still, redwoods should grow very well indeed there, and not show this type of damage seen on yours. Anyhow, we've been having mild winters but they still had some cold, windy periods. I've never seen such damage even on a smaller plant, in fact in 3 years outside I've never seen my 2 clones of redwood bothered at all. Summer or winter. They have also seen from about -12C to 37C. Maybe my loamy soils are more moisture retentive than yours? So it makes me think that the problem you are having is more with dryness than absolute cold. Maybe your soil is rocky and a fair amt. of the winter rains run off or quickly percolates through. Or even this: maybe because you are a winter wet climate, the plant really does want to start growing in winter. But then, it experiences cold spells and is damaged. Since we have year round rainfall and slightly cooler winters, they only try to grow in summer here? Just food for thought!

Yes, I should think it beyond obvious that this is a duck out of water. "Coastal"! Not "interior desert redwood", lol. I think it's fine to try things unlikely to succeed, but to get all surprised when the inevitable happens? Not so much. That's about as inappropriate a site for this species as can be. I've done things which had a low probability of working out myself. But I knew that going in. +oM

If the two zoning systems you checked indicate it's too cold or dry etc. for them there (you didn't state the pertinent details so it is impossible to comment on this aspect) then that is that. Short of building a giant greenhouse there is nothing you can do to make it work. And 5 redwoods will need a lot of space, even if planted close together (in a suitable climate area) as a grove or hedge. Coast redwoods burned when it got down below 10 degrees F. in my part of USDA 8 so I don't know about lasting success in true USDA 7. One expert thinks the species is excluded from occurring in nature farther north than it does by competition from Western Hemlock but otherwise the coastal analog from Oregon to Alaska is Sitka Spruce. Other regionally prominent Californian trees such as California Myrtle and Tan Oak that do not occur wild up here but are able to produce large specimens in local cultivation are also scorched by sharper winters this far north.