I have a location on a west facing fence that is part shade (never any direct sun - dappled at best) and stays fairly moist. I put in drainage so rot should not be a problem. It's not totally clear to me which if any clematis varieties do best in low light but I've narrowed in on the texansis group. Of course I don't expect masses of flowers in a low light area but a few blooms would make me happy and of course at a minumum I would hope for 4' of growth. I saw one post here that claimed a large flowerd hybrid produced lots of blooms in ful shade - I'd have to see that to believe it. Anyhow, I already have a few large flowered varieties and would like to try something different.
My usual supplier has these varieties -
crispa (pre 1726)
Duchess of Albany’ (1890)
Gravetye Beauty’ (1900)
Lady Bird Johnson’ (1984)
Princess Diana’ (1984)
Sir Trevor Lawrence’
I kind of like Kaiu (small white pitcher shaped flowers, sort of a dainty woodland look) but if I wanted a little color I might be tempted to go with a Lady Bird Johnson or similar. Some types have upward pointing flowers while some are downward. Does this vary with the plant or age of the bloom or are they fairly consistent within a variety? Reason I ask is if I get 2 different types it might be best to have both upward or downward facing since they are next to each other.
Clematis for part shade
Chalk Hill Clematis Nursery talks about Clematis that do well in a partially shaded environment. I copied & pasted this from their website.
Clematis For Partial Shade and North Walls
Most clematis require at least a 1/2 day of sun or strong filtered light to bloom well. Gardeners living in warm weather states such as California that have very long growing seasons and very hot temperatures can plant most clematis in a partial shade aspect. However, those living in colder climates with a shorter growing season need to adhere more closely to the following recommendations. The varieties below are only some suggestions and by no means represents all the varieties that can be grown in partial shade.
You may want to take a look at their list. http://chalkhillclematis.stores.yahoo.net/clematisforshade.html
I did get a lot of blooms from my "Sunset" clematis last summer. It got only 3 hours of sun (I timed it).