It doesn't make sense to "protect" something that potentially gets gigantic, beyond its first couple of years. How are you going to keep protecting it in 20, 30, or 50 years? You're not, unless you do this:

http://cdn.c.photoshelter.com/img-get/I0000dUeSjC_9oTc/s/600/600/Kamelienhaus-Pillnitz-Dresden-Germany-1.jpg

Your post is somewhat incomprehensible but if there's a "Sequoia" in a "full zone" colder than zn 6, it's a Sequoiadendron, not Sequoia semprevirens. Sequoia semprevirens is only hardy in zn 7. If it is a Wellingtonia/Big Tree, and if yours are dying in the winter - no part of the US zone 6 has had a truly cold winter last year, to the best of my knowledge - you are doing something seriously wrong. OR the plants are actually dying in summer and the death wasn't showing up until the winter. You probably should use the gardenweb search feature to find previous threads about Sequoia versus Sequoiadendron and where each can be expected to grow.

I do read of conifers, and things like boxwood, being wrapped for wind protection in very cold zones. I can only assume it works; but others who actually have experience with doing this will have to chime in.

For a post like this, you need to specify where you are down to the nearest large town, and use the scientific name to clarify what plant you are discussing.

My hope is if I can get them to survive a few winters they 'may' toughen up a bit

==>> no they wont.. and you will still be living near that river called de nile ...

i appreciate your drive and ambition.. but you will NOT win .. period ...

ken

ps: you said: due likely to cold winter winds dessication

and how did you come to that determination.. as compared to the roots dying.. and with the lack of water.. the exposed part desiccated????

pps: a simple cardboard box.. open at the top.. and held in place with a couple stakes.. will create a no wind zone .. while allowing no retained heat .. NEVER USE PLASTIC .... in the alternative.. a rose cone.. with the top removed is even simpler ...

Sorry I neglected to mention Sequoiadendron giganteum... these are seedlings not a known hardy CV. Afraid it was late when I wrote that.

So yes, there is a Sequoiadendron a full zone colder than mine that I keep an eye on. I'm going to guess 20 years old.

Why do I think mine die of dessication? Because I live in a very windy location, and in winter those winds are cold.

Fall/spring are moist, they don't dry out except mid summer.

It does make sense, many species are sensitive when juvenile - with less hardened off tissues etc., but can survive colder temps when older. We see this all the time around here in North Florida. There are plenty of Washingtonia around here, but I have never seen one less than 10' tall. I have tried numerous times with seedlings, they all die in winter. Yet, 1 mile from my house there are mature 50' tall specimens. I would say if you can provide a location with some winter shade, that will help. Also refrain from fertilizing and cut back on watering in the fall. Mulch it well and if possible, construct a burlap wind barrier.

The biggest make or break provider when growing out of zone is your micro climate. It can vary one zone up/down in your own yard. If you don't have that area that provides the extra covering protection then sooner or later your conifer will perish.

A micro climate is simply the local climate on a small scale. Micro climates are formed by hills and valleys, structures, paved areas, hedges, etc. These features may change airflow patterns, alter day length or light intensities, trap heat during the day and slowly release it during the night, or in other ways modify local climate.

These 3 things need to be considered when growing plants adapted to a hardness zone warmer then your own.

Location: Planting your warm-climate plants in a sunny, south-facing location against a fence or sun drenched wall will counteract the effects of shorter days and cold north winds.

Shelter: Taking the time to tuck your plants in close proximity to a wind break screen again facing south is help full

Mulch: A thick layer of dark-colored mulch keeps frost out of the ground and allows the soil to warm up earlier in the spring.

Forget the overwintering for the first few years. That won't get it. Only providing the above mentioned protections on a permanent basis will insure a better then average survival rate when growing out of zone.

Dave

Dave I agree fully with what you wrote there.
Sequoiadendron get complicated in that they outgrow your average microclimate. I once had a Sequoia sempervirens survive a couple years below the snow level. Until one year it got cold with no snow over.
I'm pretty sure this species is hardy in my location, it just seems the young nursery stock is too soft (over fertilized, grown in greenhouses...?) I have used several sources now without luck.

After a full growing season without fertilizer, plus with the hot summer sun, some drought, and quite a few light frosts, these trees will hopefully now react like any other Z6 tree in Z6.

I don't know where you are located, dirtslinger, but if you're in the Eastern US, you have a lot bigger issues than cold - summer heat and humidity wreaks havoc on Sequoiadendron.

"summer heat and humidity wreaks havoc on Sequoiadendron"

I think they would be fairly easy well N&W of say Bucks Co., PA or coastal Connecticut. In other words if you are inland enough to be 6a (5b areas at some elevation are probably ideal) or colder and north of the Mason-Dixon line, they will not have such problems except in very hot years. Maximum summer high in Altoona is around 81F IIRC. Larix decidua is used for forestry those parts. The most southerly that look good are the ones at zn 6b Longwood in extreme SE PA.

Salicaceae you extremely confused me for a moment by discussing Washingtonia, a palm whose scientific name reminded me of the common name Wellingtonia used for Sequoiadendron. I am surprised to know some clone of that palm cannot be established in your area, perhaps W. robusta X W. filifera cross. I wouldn't say they were common in New Orleans but if you kept your eye open for them there were plenty about. The varying trunk thicknesses makes me think some of those were hybrids.

I planted (8) Sequoiadendron in various locations (all tucked in with native shrubbery to give them dappled light all day) two summers ago. All eight were dead before Fall! I also watered them as I should have. Of course that was a brutal summer for us midwesterner's. Still, I won't do it again. My Metasequoia's all flourished thru that summer, and last summer, which wasn't much different, just brutal; the Metasequoia's were planted three summers ago as 1-year plugs, and they didn't receive supplemental water, not a drop, the two years after they were planted, and in full sun.

Good luck though dirty! ;-)

Dax

In NJ that bacteria which comes along with the heat and humidity really kicked in this year, after mostly avoiding my Sequoia during the previous 3 summers (planted Fall 2009). Of course this summer broke records when it came to rainfall, so it really is the "warm humidity" that does it in. Note: highs actually weren't that hot, I think this summer came in a little below normal, but 70s and 80s with humidity is just not something Sequoias experience in California.

The roots of Sequoiadendron are killed at soil temperatures not much below freezing. Successful growth of Sequoiadendron in zone 5b & 6a is usually associated with areas having reliable snow cover, usually in the lee of one of the Great Lakes and receiving a lot of Lake effect snow.

The roots of Sequoiadendron are killed at soil temperatures not much below freezing. Successful growth of Sequoiadendron in zone 5b & 6a is usually associated with areas having reliable snow cover, usually in the lee of one of the Great Lakes and receiving a lot of Lake effect snow.

Try the cultivar 'Glaucum.' There's a nice one growing in the arboretum at Gee Farms.