I have read differing values for the hardiness of these plants. Many places say zone 7, but Buchholz indicates hardy to -20 degrees, USDA zone 5.
Other than risking the ones I have, any suggestions?
No way zone 5. Zone 7.
There are cultivars of Karl Fuchs selections that are 5b/6a.
these were found in the high elevations of Afghanistan.
Cedrus libani var. stenocoma is another true cedar hardy to zone 5a/5b.
Thanks for the info. From what I have been able to find, these are much larger than what might be termed "dwarf," and so will not work in my garden.
Depends what cultivars you are looking into. I did quite a bit of digging and found people growing them in zone 5 with success.
I'm trying a few to see what happens.
I live in colorado on the front range north of Denver. I planted a six foot Karl Fuchs four years ago in my backyard. So far it has endured not only -23 f but also the driest winter on record. It came through a hailstorm that hit last spring with close to baseball sized hail. It is now fourteen feet tall and going strong. It is in full sun but gets some protection from NW winter winds. I would say no winter burn here where green giant arborvitae gets south burn and grows out of it this gets none. I would say it transplants better from a container than from b&b. It is an amazing plant. My neighbor has a 3Ã¢ÂÂ³ autumn blaze maple planted just south of it and the cedar is outgrowing it vertically.
Your cedar will grow quite well in zone five. I live in central Michigan and have no less than 15 of these trees planted on a two acre lot, the oldest now ten years old. We experienced at least minus twenty twice in that time period and none of these trees has had any damage. My cedars are growing fast and soon I will, with regret I will have to cut the oldest one down, now thirty feet tall. This is because listening to all the misinformation on their ability to take the cold winter I planted the tree to close to the house believing they need a lot of protection, THEY DO NOT.
I have C.d. 'Devinely Blue, 'Feelin Blue' and 'Prostrate Beauty'.
In my zone 5b, I have experienced needle burn and needle drop the following spring. Divinely Blue is on the south side and feelin blue on the east side. Both are slightly protected. Burlap screening should by you the protection during the first 3 years.
Correct Will. It's the hardy ones merlinus needs.
Our resident expert Resin has told the same story over and over again about Cedrus deodara in Denmark that went thru a bad winter and it decimated all of them. The area they were in was a zone too low and that one nasty winter was all it took.
As I said, the Karl Fuchs selections are the ones to grow. I'm not going to "argue" about zone 5a/5b for them. 5a should be fine, as well. :-)
I said 5b earlier just cautioning to the safe side.
As I wrote earlier, the hardier ones are far too big for my small rock garden. Per suggestion, I will use burlap to try and offer some protection to the ones I have if the forecast is for very cold and windy weather.
Google zip code 98908 for weather history. I planted a standard "Aurea" at my g'mas ranch 20 years ago (2,500 feet). Looks great - enormous now. Lost some needles in the early 90's but seemed to adjust and really get going after that. That and the Atlas cedars seemed to need a few years but then look out!
As far as dwarfs, buns, and brooms - curious how hardiness is determined. Is it the rootstock or the graft? We have this issue in apples as well.
It's both. I've been told two differing accounts about the root-hardiness of deodara, however, zone 5 seems to be OK for their roots. There's certainly no reason that Cedrus libani var. stenocoma could be used to graft the hardier deodara's onto, it's just that grafters would need grow their own seedlings which isn't a norm.
As I said manastash, the hardiest deodara's were brought to us from the highest mountains in Afghanistan where it truly (is/has to be) a zone 5 situation. That alone accounts for the reason their buds/needles are hardy to zone 5.
Surely with any other describable situation, i.e. apples, if the roots aren't hardy to your zone or vice-verse the stock grafted to the roots isn't hardy to your zone, you're going to lose one or the other.