Boy you're gonna get it for asking about this! Ask me how I know.

Joe, my garden is in zone 8. I planted in an exposed position (cold north winds) 3 years ago a one year old seedling. First winter I protected it with frost cloth, which failed to last till spring so I got a brown seedling. It greened up nicely in spring. Next two winters no protection at all. The browning was less but very evident!
that's second winter

For you (zone 7) I suggest both spray the foliage and use frost cloth at least for the first winter.

Best regards,
Fotis

If the one in the picture was mine I'd mulch it. It wouldn't spray it.

Well, next early spring I cleaned the base of the tree and applied more than 2in of mulch with top soil from Abies cephalonica forest (decayed needles and cone parts) and Abies cephalonica bark from fallen trees. Next winter it still fully browned but with a bit less intensity (which i attribute to further establishment)

Here is the same tree 3 weeks ago - 3m height with more than 60cm this year's growth!)

best regards,
Fotis

It would seem that (at least some) members of the former Taxodiaceae has the ability to brown in winter, and then turn all green again in spring. My Cunninghamia does exactly the same. Amazing.

My Cunninghamia browns (or purples) in winter too, even rather mild ones.
But on Sequoia semprevirens the few needles have seen turn brown, stay brown. The have to be replaced. Fotis does your tree replace its needles or do they actually go from brown to green?

It's interesting to me that here, where Sequoia sempervirens is endemic, brown=dead. Wonder if it is an adaptation strategy? Is there a known reason for certain genera such as Cryptomeria, Cunninghamia, Microbiota etc turning color so dramatically in cold weather?

Does the chlorophyll disappear or is it masked by another pigment?

Sara

David, the needles although brown, after close inspection, you can see they have green in the inner protected parts and they are juicy not dried out and stiff. 95% of the needles actually turn from brown to green in 3-4 days, completely alive. Only very few of them die out and fall later in spring. Has done it 3 winters now (along with a few other seedlings-cuttings I have, with a bit less intensity as she establishes further.

Best reagrds,
Fotis

Thanks for the update Fotis. Since they are being discussed anyhow, here at the trees on the campus of W&M in Virginia. They were once measured at almost 100', but based on examining them I have a feeling both have lost parts of their tops. (one is definitely known to have lost a huge part of its top in Hurricane Isabel) They seem fatter than they once were, and not as tall. I noticed one had a divided trunk that should not have been allowed to develop. Plants that they used to tower above, like a Pinus taeda and an Asian Quercus, are catching up.
{{gwi:767834}}

These showed no apparent injury after the winter of 1994, when it was so cold all the fountains and ponds in Williamsburg were frozen solid. That Ficus pumila you see on the brick wall was blackened. The Trachys on campus had about 50% leaf burn. Low was 0F versus -4F to -9F in the DC area. That was the last winter it was cold enough to walk across the Potomac from DC to Virginia.

This post was edited by davidrt28 on Mon, Jul 29, 13 at 20:56