It seems to me you will need a planter or tub of some size to support a climber that grows as large as this does. It is not a small plant at all. Even something that might be called a tub is probably going to be too small.

You don't want it to grow for years and then die out because the container was not big enough to keep it going over the long haul.

What do you think of starting out in a large plastic pot with the bottom removed?

It will grow into the ground and then what do you do?

Yes, not the type of clematis suitable for growing in a container, especially if you want it to climb into a fir tree. It could be done but only if periodic root pruning were undertaken - in effect bonsaiing the vine and reducing its ability to climb unhindered.

And I'd opt for something the size of a half whiskey barrel minimum for a clematis this robust.

Dotty is that a retaining wall behind the fir tree, if close enough you could try planting a clematis behind the wall if it's not paved and train it towards the tree.

Annette

Yes, it is a retaining wall but the bed is full of hypericum. I can try clearing a spot for the Montana but it will have to compete with this stuff. That likely is the best bet, it's not too far away. Thanks for the suggestions everyone, I truly appreciate your thoughts.

Dealing with the hypericum could be an issue, if you decide to give it a try you'll need to put some kind of barrier to stop the hypericum roots from crowding out the clematis.

Annette

Well the Montana is now residing in the bed with the hypericum with a trellis leading to the tree. I know how invasive the hypericum is and I know there will be difficulties for the montana to compete. However, I'll give it a try -- right now I have so much to do I don't have time to do it right. Springtime is so full of jobs waiting to be done...