I grow virtually all my conifers in containers. And they are outside exposed to the elements all year long. But I live in a very different climate than yours so I have no idea how any specific selections would fare during your winters. And I live surrounded by woods so 'unsheltered' is not exactly a factor nor is the chance of excess or strong sun.

Almost all of mine are dwarf cultivars but they do run a gamut of species - pine, true firs, cedar, podocarpus, cryptomeria and chamaecyparis. And a fitzroya!!

@ken_adrian

Thanks for the reply, but wouldn't some stuff do better on a unsheltered southern exposure vs somewhat sheltered northern in winter.

E.G the blue spruces I had in a pot before always did fine regardless of the exposure and how sheltered the location was.

BUT

are you suggesting that if I left my Dwarf Alberta Spruce's on the southern unsheltered side, they would do just as well as when they are on the sheltered northern side?

Because I always keep them in a shaded northern side in winter and they do well, no damage but I see ones that are exposed and south side that neighbors have in-ground that get a bit damage over the winter compared to others in different locations/exposures.

And for example if I look at pines in general over the winter mugo pines and jack pines look a bit better and greener overall than say the eastern white or red pines...I know that they are in the ground but wouldn't that be related to weather conditions?

Thanks for the clarification

There are issues with the root hardiness of some plants left outside in containers in colder climates. Typically, roots are far more vulnerable to cold damage than is the top growth and generally at higher temps. And since the roots are more exposed to cold ambient air temps in a container than they are if planted in the ground, cold hardiness of certain species would be a concern.

btw, most large wholesale growers of conifers (and most other woody material) realized a long time ago that bark based potting mixes were far superior for their plants than the water retentive peat based ones. I don't know any growers that still use the peaty stuff.

your D A S are known for burning in winter sun , but their roots are very hardy

some other picea glauca would be appropriate, as would picea omorica

or lots of pines

ron

I imagine you realize that to grow them outside over winter in pots the first check is are they at least tolerant to 2 or 3 zones colder than your own. So you in 6B (sigh! I remember those days I'm only 4B now) you'd need 4B or lower as a starting point. I wonder if the lower the zone, the more tolerant to the winter abuse of drying wind, sun exposure etc. I applaud your ability to grow these successfully in pots. I have heard that you can spray the tops with a anti-dessicant to help with the wind burn. I've seen so many Alberta Spruce burned and yellowed that seem to be perfectly sheltered from sun, and wind and in a warm enough zone. At my house the deer eat every cedar that they can find above the snow line so I would never dream of having them in containers, but more power to you. One of my favourite is Danica cedar because it has a nice tight round shape, but my soil is a clay, so perhaps cedars in pots would be too "well drained". Have you tried any cedars in pots? I would think the Mugo pine would be worth a try. It's one of the less expensive of the mountain type pines.

boy my answer above sucked.. lol ...

winter damage is not just about sun ... it is also about winter winds ... and temp fluctuations ...

in mid winter.. a plant .. in your clime should be dormant.. get it dormant.. and keep it dormant ...

the problem with evergreen type plants ... is that you get these sunny comparatively warm days.. and the leaves can that ... and then they refreeze at night ...

plus the drying effects of winter winds ... and you have a recipe for freeze dried evergreen leaves ...

in a sense ... with the multiple variables ... the choice of stock might not matter ...

your best shot.. would be to try to find stock that is 2 or 3 zones colder than your zone .... which i now see mary above mentions ....

when i started with conifers.. in the ground... damage tended to appear in mid to late spring.. when the temps started warming.. and that is when the evergreen tissue started browning ... i found it very hard to figure out.. when the actual damage occurred ... and to assign a reason ... especially since in my MI.. i did a lot of fall planting ...

one thing for sure.. as the plants aged .. over the years ... the more established the plant became.. the easier they could overcome the effects of winter ... and one very important thing in all that.. was that the plants went into winter.. full of water ... in other words.. in prime shape... especially if it was a drought year ...

and that is part of what i was getting at.. in my first reply ... the plants need proper watering.. with proper drainage.. late into fall ... but the media can not be holding so much water .. that you freeze the roots into an ice cube ...

and yes.. DAS are carp plants ... over marketed and ridiculously cheap due to such ....

perhaps you should stay with them.. keeping in mind.. that they are semi disposable ... just replace them every few years ... due to your location issues ... i suspect some winters you will win.. and others you will lose.. and that is simply the odds you are going to have to accept... in your situation ....

ken

I just looked up the Dwarf Alberta Spruce. Apparently it is zone 2 so hardiness should not be an issue for many of us growing this in or out of a pot. So although zone is a consideration it's obviously not the ultimate determining factor. But, you know that far better than I do. :) I don't grow any plants that overwinter in pots outdoors. The bit about at least 2 zones colder I learned from a show I saw that was talking about pots on balconies in high rises. So I imagine any information on pots on balconies in high rises could be helpful even if your pots are on the ground. The same issues - winter cold, sun and winds would be considered.

For evergreen planted out in the ground itself, Ken and some others are right about adequate moisture in the soil. How often have we seen a whole hedges that completely browned in spring on one side? The sunny side. As we don't notice this till the spring is seems a mystery because by spring the soil is damp. This is especially bad with cedars because they naturally grow in moist soil in the wild. So, if they go into the winter without enough water we only see the damage come spring. I always advise anyone planting an evergreen close to the house on the south or west side to cover it with burlap or something for a few winters so it doesn't brown. After it gets older, like others have said it is less an issue, more tolerant. That, on top of a good late fall watering of the soil, which of course you already must know if you grow plants in containers on a regular basis.

I imagine you also use pots a large as possible to avoid the soil drying out too fast. So, like the cedars that like to grow near the swamp, what sort of evergreen likes to grow in a well drained exposed site? Perhaps those that like Sandy soil — Scotch pine, mugo pine, junipers.

Thanks for remembering this thread from early october.

I found a really nice Blue Star Juniper on Standard (Tree form).

I had it out on a south facing deck most of October and November and then moved it to the front porch for the winter. It has been a very warm and wet winter so far with all snow melting soon after falling, and has only now begun to actually get cold.

I moved it to an unheated garage temporarily maybe twice so far when it got unusually cold and windy, along with my dwarf alberta spruces and a euonymus I have had growing in a medium pot for the past 4 years.

So far the blue star juniper is doing great, even looks better than others in the area so far...hoping it will look do good this winter and look okay in the spring as well.

I'm still thinking about getting some kind of Pine this spring or whenever I find what I like to grow in a pot.

Makes me feel good that it doesn't get as cold as other places where I live and that I have a large unheated garage (which is usually at least a degree above freezing even on those record cold days we sometimes get during some of the cold winter years) with plenty of space to use for my potted plants in the case of record cold and storms

It seems that any question related to over wintering plants in pots inevitably brings out one of the most enduring myths in horticulture: the idea that a given plant's hardiness rating determines its winter survival in a container. Most commonly it's expressed in the "two zones hardier" claim as above. Hardiness ratings apply to a plant's above ground parts. An Alberta spruce may endure Z2 lows when its roots are protected by the thermal mass of in ground planting. In a container, it does not have this protection. Alberta spruce (and the vast majority of woody plants) roots die at a much higher temperature than the indicated lows for Z2- probably in the +10 to + 15 range. In a prolonged period of deep cold containerized plants can die because their roots have been killed by cold. Doesn't make any difference at all that it was 2 zones hardier.

When I was looking for an evergreen for an outside urn in my zone 6b, my nursery said only boxwood would be reliably hardy..

This is the Gardening in Canada group right? gardenga Zone 8/9 - where are you? Oh, sorry, that's right we get multiple forums for each post now. Frankly, boxwood surprises me as a recommendation for a winter outdoor pot evergreen. Thoughts AW? At my house even with the hardier varieties of boxwood in the soil the leaves burn even though they are relatively protected. But, I"m out in the country. close to the coldest capital in the world. Yet, I can make Rose of Sharon survive. Maybe other folks have different experiences with boxwood. But, hey I"m all for experimenting. How did it do so far kitasei?

Mary, this was cross posted in several forums....so shows up and draws comments from a much broader audience than just Canada :-)

In my area, on the border of z 4 and 5, I haven’t found any woody plants or seen any in other settings that are content in a container. So I use cut stems, a combination of bright or interesting deciduous stems with evergreen branches, often supplemented with lights, ribbon, or other ornament such as an iron obelisk. The only drawback is that it either needs to be done before the soil in the container freezes or in a thick layer of floral foam that is then fastened into the container. Mine last well into about March, so my goal isn’t a holiday container but one decorated for winter.

Deborah Silver, a Detroit area landscape designer, is a master of this. Here is one of her posts from this winter on her winter containers.

http://deborahsilver.com/blog/the-winter-ahead/

There is a search bar down below the comments for this blog on my tablet, though I am not sure if it is in the same spot on a regular computer, so if you want to look at previous years’ posts, put in the term “container” which will get you ideas for all 4 seasons for large pots and window boxes. At various points she has shown detailed instructions for how her team assembles these containers, so that may be of interest.

I do what nhbabs does, also inspired by Detroit Works. The arrangements are far larger and more interesting than any conifer or boxwood could be. I use dried hydrangeas, grasses, evergreens, curly willow, ivy, you name it! For a plant to survive here in a pot, the pit has to be bigger than the plant. It always looked pathetic.