It would not be something I'd advise :-) Of all the clematis I have grown, armandii is one of the least suited to container culture. Big vines typically translate to big root systems and armandii has the largest root system of any clematis I've worked with -- far larger than what a half barrel would easily accommodate.

I'm sure you could keep it in a container for awhile but a restricted root run will result in a naturally dwarfed plant and so I would expect stunted growth and most likely lackluster flowering. And there would be a need for regular root pruning -- a lot of work with a vine like armandii.

And by moving it to "a bright window in the winter" I assume that means the plant is not winter hardy in your zone? When would you be able to move it outdoors? It has a very early bloom season that can be affected by hard frosts in cold climates. And it would outgrow a 5' trellis in a single season.

Can you explain where you are located and maybe there's a way one can work around these restrictions. But on the surface, it doesn't strike me as a good plan....sorry :-)

Have you considered a variety like xcartmanii 'Avalanche'? This is also an evergreen selection with a profusion of early flowers much like the white form of armandii ('Snowdrift'), but it is a much more compact plant with a much more condensed habit (8-10 feet compared to 25-30') and with nice, smaller, lacy foliage too and is far better suited to being grown in a container.

Damn - I was afraid of as much. I'm in zone 5 - sunset zone 41.

I've just really fallen in love with apple blossom, and have been envious of all those growing it. Suppose the grass is always greener.

I have 'Apple Blossom' and it just isn't one I'd pine over if I lived somewhere too cold. Not that impressive. The foliage gets ratty and it blooms for a short time.

I guess it's a good thing we all have different preferences - keeps life interesting :-) Armandii 'Apple Blossom' is one clem I would not be without in my garden - very heavy and fragrant bloom that lasts a good 4-6 weeks and very handsome evergreen foliage. Unless it gets a lot of winter wind, the foliage on mine is untouched by winter. Of all the clems I grew in my old garden, this one was a real traffic stopper, probably because of the impressive size and prolific bloom.

But I agree that it is not a good choice for colder areas and even less as a container plant.