I would try that making sure to use a nice well-draining medium and keeping the leaves well watered or misted. If you had a slightly shadier spot with surrounding vegetation that might also be better, but I'm usually doing this Spring, Summer and Fall as opposed to Winter. If you have enough cuttings I'd try some in the ground and some in pots to hedge my bets. Perhaps use an inverted soda bottle with the cap removed to help hold in humidity. As Sheila alludes, buying another might be better, not only because rooting can be iffy, but also because it can take a while to grow a cutting to planting size.

I can not think of a blue/red/purple clematis that wouldn't go with New Dawn. I grow Jackamanii in a rough spot. It is small compared to New Dawn so maybe two plants would be needed. Better to get a second opinion on that. The box clematis will take a few years to grow in, maybe three years to flower. You might want to splurge on a potted plant at a local nursery. Around here they run about $20 or less. You will find them at any nursery, even Home Depot. New Dawn blooms on old wood. It is suppose to be a repeater but most find it doesn't repeat reliably. Mine has only once repeated a single flower. You can prune dead brown canes anytime but if you want flowers, wait to prune New Dawn until after the main flush in June. Also choose what canes you are going to train on your trellis and cut off the rest. I've gotten advice to prune down anywhere from 2 - 4 canes from different sources. A nice reference for training roses is Stephen Scanniello's book "A Year of Roses".

I have become convinced that ND is not suitable for an arbour unless you combine it with a swag and then diligently train the canes onto the swag. In late July we will be cutting our ND back completely, to the top of the arbour and starting over, swagging every cane of a suitable size from the begining. The consensus of rose folks seems to be that ND will survive the treatment. We didn't start swagging our ND until there was already a thick accumulation of canes on the top of the arbour and dangerous tentacles reaching out everywhere - those thorns are NASTY! Even with the swag, the volume on top of the arbour has grown, because it's not easy to work with the stuff up there because of the thick tangle of older canes - not to mention at least three different clematises... I am concerned at this point that ND will bring down the arbour/south alley gate if we don't do something about it! So it's time to clear the slate an start again. My advice is only go for it if you've got an appropriate set-up to control it and are willing to be diligent in controlling it (which we weren't for the first few years, and then it was too late...) Given our experience I really think the appropriate place for ND is trained along a relatively low fence (4' or so); tie it in to the fence as if the fence was a swag. A low fence would make it easy to work with it - as opposed to needing a stepladder in the case of an arbour. Good luck.

Cecily, thank you for sharing your experience! One of the reasons I chose New Dawn was because it would cover the trellis quickly. My thought was that at least I would be able to enjoy it for a few years even if I need to remove it in order to replace the a/c at some point in the future. However, I think I would be sad to see it go and since everyone seems in agreement with you that it is a bad idea to plant it in this spot, I am going to move it to the front of the house this weekend, where it can go wild over the roof of the porch. :) The question remains what to plant in it's place, though? I really would like something that will hide the a/c units from view, but I think whatever I plant I will run the same risk. I'll have to give it some thought, but if you have any suggestions, please do let me know! Thank you.