Clematis montana

Well it definitely does seem to be a montana from this distance.

A couple of times I tried planting deep purple Clematis at the front of my house, tacked a trellis (sp) up for it had high hopes... They just didn't like it there. I think mostly because they only got the morning sun.

Could you suggest something that thrives in shade or low sun area? I've tried to do some reading on this so when planting season came along I would be ready, but I'm afraid I don't have the time to get really involved.

Speaking of Montana, this surprised me so much! I saw a neighbor digging up a plant with the most beautiful
yellow blossoms and when I asked what it was (Day Lilly) she gave me a small portion! I wouldn't have believed something so wonderful could grow in Montana!
This Day Lilly has bloomed and expanded (without much help from me!) for four years and last fall I added two more - a beautiful Red and a heavenly White Lilly! The yellow has given me such pleasure that I wanted to share and was able to take parts of the new plants to give to my sister and a friend! I am so excited to see what they do!!
Zibbey

In this case, Zibbey, 'montana' means that in nature it grows 'in the mountains' rather than in the state of Montana. Clematis montana is actually native to the Himalayan regions of China.

There are clematis which do well in part sun - Hagley Hybrid, Nelly Moser are two which spring to mind. Dr. Ruppel and Bees Jubilee do better with less sun, retain their colour variation longer, as does Niobe. All of these are hybrids, so they don't get enormous like the clematis species do - average height and spreads are roughly 12 feet by 4 to 6 feet. Bear in mind, though, that Clematis will not grow up a trellis - they need thin supports to twine their stems around, so something like clematis mesh would be better - you could staple it over the existing trellis though.
Otherwise there's Hydrangea anomala, but you'd have to check whether that would be fully hardy where you are. It's certainly hardy here, but I have a feeling Montana gets very cold indeed.