Well then, these results seem to indicate that the simple windbreak idea may not be a very good idea especially for New England.

Citradia, you should try a hardy pomegranate like Salavatski they are significantly more hardy than Wonderful and are supposed to taste very good. My Salavatski made it through its first winter undamaged with only a burlap wrap. There's also a guy that grows them in Allentown/Bethleham PA unprotected and they produce fruit for him.

Citradia, did you use white plastic to keep the sun reflected away from the plant? I was thinking that waiting until the plants are fully dormant...for me up here in Maine probably in November (maybe push into December)...and the cylinder of white plastic to keep wind and sun off might help significantly by keeping the tree dormant all winter. I've watched some of my native super hardy hemlock trees take winter damage where the sun hits the trunks if we get a little "warm" spell in the winter. The trunk ends up taking serious freeze damage and splits.

I am at 3000 ft on top of mountain in a north western wind tunnel between two mtn peaks. My low temp last winter was 19 degrees which lasted over 24 hours with ice storm and power out. My Russian pomegranate that I planted last spring survived without protection and now is growing like a weed. We had cold spring with temps in 30's and low 40's up until May. My Thomasville was the last citrus to break dormancy and is finally growing. My Kimbrough did great in 6mil plastic "green house" with roll up sides and roof for warm weather ventilation and large black plastic garbage can full of water. My plastic is clear.

I didn't think hemlocks cold be damaged by cold. Mine do fine and they are native here. I've seen what I presume to be winter damage to south side of trunks on apricot trees and silver burch and lost one apricot last spring but I wondered if it could have been borer damage or poisoned by "round-up".

I know! I didn't think the hemlocks could be winter damaged like that either, but the winters have been a bit sporadic lately...had some fairly warm spikes that have lasted for several days and the following spring I've seen the resulting damage on my native hemlocks that were on the northern side of a clearing...trunks were fully exposed to the sun and the trunk had splits on the south side. Same happened to a few of my sugar maples. All are healing up pretty well.

Citradia

Perhaps your Citrumelo was not fully dormant since your in a warmer climate? Your 19F sounds so warm for a low temperature. We probably had a daytime high temperature colder than your 19F. My gut tells me your Citrumelo was not fully dormant?

No. They were all dormant with no new growth since August. The citrumelo was fine. My newly grafted Changsha mandarin is the one that put on two feet of growth last summer, went through most of winter with same 2mil plastic wrapped cage around it with venting opened on warm days in 50's. after 80 mile an hour freezing winds tore my cages loose and trees on slope above fell on my enclosures, I decided to go with the L-shaped wind breaks sometime in February. After the 19 degree ice storm that lasted at least 24 hours, I noticed the mandarin looked burnt at the top and has been gradly dying back ever since. New growth has appeared but the base of the graft wood turned yellow and now dark brown and the brown is moving up the grafted stem/trunk and I noticed the new growth wilting yesterday. Another grower told me they've seen that on theirs and thinks it is a blight. I think Changsha not hardy enough for me.

Looking on weather underground at the temps in your area last winter, I see that there were around 10 separate cold snaps with lows in the mid 20's or lower and you had a total of around 30 days w/ lows of the mid 20's or below. I wonder if this is not the culprit for the initial die back. Generally when the cold hardiness of citrus is discussed the hardiness temps that are mentioned are only the coldest temps which that cultivar survived in a one time freeze. Depending on variety, dormant citrus can tolerate relatively cold temps, even into the teens, and recover nicely, if it is a one time event. If there are multiple freezes, a cold acclimated citrus uses up most of its cold tolerance in the first round or two of cold temps in which the plant tissues freeze. After this it significantly more susceptible to freeze damage. I would think the Changsha would be fine if you protected it like your Kimbrough.

Thanks for the info. I do get plenty of chilling hours here. My apples , cherries, and mountain ash do very well.

An update of the Citrumelo from today

Tim, looking good, it seems to have put on some significant growth.

Hi Scott

Yes....the Citrumelo must have grown at least 2 ft

I wonder if I could get by using passive protection on an in-ground Satsuma here in zone 7 on the south side of my garage. Any ideas? We can get down to 0 degrees every third or fourth year or so. Maybe also graft onto P.t.

If you can cover it & put a light bulb in the enclosure you should be able to.

Harden off satsumas can withstand temperatures into the low 20s. So with some protection and passive heat protection, they could do fine. - Millet