Input on plants for privacy screen

Hello! This is my fist post as I just joined, I am living on the west coast of British Columbia and we (my wife and I) would like to put some planter boxes on our patio and a latice so we can plant some sort of vine or anything leafy that will provide a privacy screen from our neighbor. It faces north and it is a covered patio. Originally we were thinking bamboo but we were told that it needs constant watering, plus there's the spreading issue. Anyway, can someone recommend a plant for us? Flowering would be nice if it's possible it does get morning sun but the rest is indirect. I took this photo at 3:30 in the afternoon to give an idea of the space and lighting, any input would be greatly appreciated.

Clematis is a good one. Blooms in the spring then it's foliage until winter hits.

If you don't mind annual vines then Black Eyed Susan Vine (Thunbergia alata) and Mandevilla provide seasonal colors. The mandevilla can be brought inside for the winter.

You can purchase the clumping type of bamboo (not a runner). http://www.bamboogarden.com/Hardy%20clumping.htm

I think Clematis would work well there. Morning sun is perfect.
There are many types. Clematis have been divided into 3 pruning groups. I tend to like pruning group 3, these you just whack off at about a foot high at the end of winter and let it grow up each year. They grow fast in the spring, and would be a good screen in summer when you spend time outside there. Pruning groups 1 and 2 allow them to get a woody framework that persists. This sound good at first for a screen, but then you can end up with a tangled mess of bare stems at the bottom which is not attractive up close on a patio.
Some Clematis like more sun than others. Commonly available ones that will bloom in a fairly shady spot include Jackmanii' (group 3), The President, Dr Ruppel, and Nelly Moser (these are group 2).
Be a bit careful of some new varieties specifically bred for small containers, they might be just perfect, or might not be quite vigorous enough to cover the screen you have in mind.

pepper- I doubt they have enough heat and sun for Thunbergia and Mandevilla in that location-summers are cool.

Clematis will probably take a couple of years to get established and really take off, so in the meanwhile you might consider annual vines. I'm told that hops (like the kind you use for beer!) will grow really quickly, so maybe use it as a backdrop for something with prettier flowers.

If you have wide planter boxes or are planting in the ground, you could put your lattice down the middle. Then you could think in terms planting clematis, maybe a climbing rose, maybe even tall skinny shrubs like Skyrocket juniper along the *back* side of your lattice... and along the side of the lattice facing you on the patio, put annual vines that could cover the latice and give you color & privacy while the perennials get going.