it took mine 3 years of shrinking and pruning off dead stuff.. before it finally died in my z5 ... that was an expensive lesson ...

its all about your micro climate.. and that once every decade or two low temp ... whats the opposite of spike..

last winter.. we had a z4 winter in my z5 .... i guess i am glad that it wasnt 5 years larger.. and a treasured plant.. because i doubt it would have taken a z4 winter ....

if you can keep it out of winter sun.. and winter wind.. you might succeed in z5 for some amount of years

my best advice.. start small.. both with a small plant.. and a small investment.. then you dont have that much to lose

good luck

ken

Thanks for the feedback Ken. Appreciate the reply.

Sounds like it's "borderline" in zone 5, so sooner or later we'd probably lose it, especially if we have a winter like we did last year.

Probably better to go with something truly Zone 5 hardy, maybe even Zone 4 hardy just in case. Abies concolor `Conica' might be a better suggestion as I think it's listed as Zone 4.

Thanks

Dave...I can only speak for the 'Blue Ice' I am growing here in Kansas City Z.5/b.

It has seen -12F. but I have it backed up to the Juniperus v. 'Canaertii' that give it almost total protection from the cold North winds. Facing South has its benefits also. The Winter sun does not come into play with these conifers demise. They never burn. Mine are in total sun year around.

There is no max height to these cultivars...they grow till they die. Mine is already at the 15 ft. height...so the 25-30 ft. range is quite within reach and beyond.

I have 4 of the Cupressus glabra with 'Blue Pyramid' up the line also backed up against the Canaertii's.

If you can offer these boarder line Zone 5/6 conifers some protection give it a try. I have been quite successful.

Don't let the naysayers scare you off...give one a try...if successful then go for another.

Dave

I can speak for -15F in parts of NE Ohio this past winter. I have seen a few out in the suburbs that look very good. It does appear that its hardier than the Blue Atlas Cedar.

Does anyone know if Raywoods Weeping is as hardy as Blue Ice? Will it do well in Zone 6?

Thanks to everyone who has replied to this post so far.

So if I understand Nikkie and Bob's posts, Blue Ice *might* be hardy in Zone 5 provided it's grafted onto very hardy rootstock?

As Ken mentioned earlier in the thread, here in MI many of us in Zone 5 had a "zone 4" winter last year with abundant subzero cold and windy conditions, the roughest winter in several years.

Unfortunately in our case, any location on our property that would allow the Blue Ice to grow to its full size would be subjected to strong winter wind and cold with very little shelter. We also have a large deer population so that might be a big issue as well.

Although I wouldnt mind trying to grow one, I wouldn't count on it surving more than a few years, especially after hearing Ken's experiences. In Zone 5b or 6, possibly with some shelter, having a Blue Ice might be a great idea. Here in MI, it might be a risk.

Thanks

that isnt what bob said...

he offers that understock should be Cupressus leylandii

but if you google the zone for that plant.. its also z6..

so i dont know why a z6 plant.. on z6 rootstock.. will make it any better in z5 ... unless i totally misunderstand his point ...

i know that some try to get z6 scion to z5 standards.. or lower.. by trying hardier rootstock ...

ken

Arizona Cypress in general are listed as hardy for Z7-9. Blue-Ice is an Arizona Cypress cultivar that is more cold-hardy than the general species, as I understand it.
The Plants National Data Base lists the species as cold-hardy to -13 F.
As for height, there are quite a few Arizona Cypress down here in the 50+ ft. range. These are older trees that do not appear to be the popular Blue-Ice or Carolina Sapphire cultivars.
Would have thought that the cultivars were grafted onto seedling Arizona Cypress rootstock. Is Leyland Cypress then the most common rootstock for these cultivars?

Since the leylandii is understock, hardiness is not affected.

I typed this wrong. I meant to say that Since the leylandii is underGROUND, hardiness OF THE CUPRESSUS is not affected.

The species Cupressus is not used for understock because the root system is too poor for it to survive field digging and it is hard to tolerate to conditions for container growing.

Earlier grafters noticed that 'Blue Ice' grew to a saleable size when grafted onto Juniperus and/or Thuja, so they spread the word that those genera were suitable understock. They aren't.

When I visited Australia, where Cupressus is major landscape genus, I discovered that leylandii is the best understock. When I returned with some grafted plants, still growing in my landscape, I spread the word and some of my nursery friends in Oregon have made the conversion. Some haven't.

I have pictures in article I wrote on Cupressus in my older website. I show cultivars and an old graft union on 'Chapparel'.

From a commercial standpoint the Leyland would also have the advantage of being able to be rooted from cuttings, rather than having to bother with starting cypress seedlings and bringing them on just to get rootstocks. Use of clonal rootstock would also confer uniformity. And Leyland is very vigorous.

Which may explain why I pretty much cannot find named forms of Arizona cypress in local outlets that are not obviously badly rootbound - this also being the usual situation with Leylands.

But then, it is very difficult to find grafted conifers here of any kind that are not perched on badly deformed rootstocks.

The last one I bought, a Nootka cypress cultivar with the labeling of the famous wholesale nursery that trumpets its superior quality in its catalogs still on it at the retail outlet, turned out to have such bad roots I threw it out instead of planting it.

A rather expensive setback, but I saw no point in installing a tall-growing specimen that would be supposedly supported by future major basal roots that started out as a braid, as twisted as a section of rope, and then bent up into a J toward the surface.

In Holland we use the leylandii understock for a long time.
It's a logical thing to use this understock because 50% of it's "blood" is Cupressus.

To any who may consider the parent trees to be Cupressus macrocarpa and Cupressus nooktkatensis the hybrid would be 100% cypress.

Hi. Garden centers over here occasionally offer grafted Cupressus arizonica 'fastigiata'. I think most of these are imported from Italy. Is there a way of recognising the understock used, or does anybody know what the most likely understock would be, coming from that country? T.

Bboy,

When does the renaming stop?
In the past it was Chamaecyparis nootkatensis, then it was Xanthocyparis nootkatensis and now it's Cupressus nootkatensis.
What a big mess!
For me as a nurseryman this is a very big problem because every gardner or gardencentre is familiar with Chamaecyparis nootkatensis, it's written this way in the books.
Now we are making our clients familiar with Xantocyparis nootkatensis while it's Cupressus nootkatensis!
When will this confusion stop???

It's the same with Platycladus orientalis which it was named this way a long time ago.
Then it was renamed in Biota orientalis, later on in Thuja orientalis and now it's Platycladus orientalis again!
We can not sell this to our customers!

I think these botanic people must know and see that Chamaecyparis nootkatensis has noting to do with the other Chamaecyparis species because you can't graft them with eachother, in other words, it's not possible to graft a Chamaecyparis cultivar on a Chamaecyparis lawsoniana understock, they won't grow.
Also the cones are much differend...

I would try a Cupressus bakeri (Modoc Cypress) instead. I live in Zone 6a and it thrives.

You have to remember the definition of zone. It's the AVERAGE lowest annual temperature over a period of 12 years or so. A tree that can take it down into the minus teens is zone 6 (or even 7), not zone 5.

A lot of nurseries are now selling plants based on the lowest temperature they will take--you may not necessarily want to try to make a conversion to your hardiness zone.