Posted: 10/06/2016 at 19:21
I'd plant it now so it gets its' roots down this growing season. Plant it deeply, they like cool roots and sunny heads. You could bury a lot of the bare stem if you can dig a deep enough hole.
I'm not pruning my montanas at the moment as they only flower on old wood and I'm growing mine over a summerhouse and fence. This is the only piece of advice I seem to remember about clems, is that if it flowers before June, don't prune.
I suppose you could cut back some after flowering and it should still put enough growth on to have flowers next year.