What might be interesting is if you had a raised planter and tried some lady fern. They can grow to several feet tall with a somewhat upright/arching habit. You can check the Bamboo Forum for some suggestions of shade-tolerant clumping bamboo. There's a drooping sedge (Carex pendula) that is shade tolerant and some upright yews that can grow in shade as a screen.

What about a pink jasmine (Jasminum polyanthum) covered trellis attached to a rectangular planter. You will have privacy as well as fragrance. If you're having wind tunneling on the deck this should make a good windbreaker as well.

Would the jasmine work in part shade - the deck gets afternoon direct sun - but only for a few hours since there are lots of trees...

I think jasmine would need more light. That sounds like a big deck, though--you could go for a couple of big pots or wooden containers with substantial shrubs, spirea, say, or forsythia or any of many kinds of euonymous. Add in the height of the pot, and these will easily reach 5', and they spread out as widely. A visit to a nursery would give you an idea of what these look like, and if they'd work for you.

Would pots of Elephant Ears work?

Have a pink jasmine in container in partial shade and it is growing fine. Some garden websites even describe them as suitable as indoor hanging plants.
They should be hardy to 10-20 degrees although new growths and buds may not be as cold tolerant.

I have had both jasmine and elephant ears in part sun and they have done just fine, although the EEs may try to stretch for whereever the sun is so placing them right in that spot would keep them more upright (if that is the effect you want). They also won't require as much water when in less sun. Jasmines in particular can adapt quite readily believe it or not and I had no problems with blooming. Along the EE line, most of the arums (including caladiums), could do well in those conditions. I'm trying some calla tubers (an arum) this year so I'll see how they do!

You should check out 'Green Panda' bamboo, Fargesia rufa.

I too, would like to plant some containers for privacy. My question is this: how big does a container need to be (width and height) if it's going to support a plant that grows 5' high? I would guess it would have to be pretty big?

Hi peace rose,
I have 2 Jackson and Perkins roses in 5 gallon self- watering containers on my deck that are up to about 6 feet (because I did a less than satisfactory job at pruning them last year) as my accidental screens. They seem to be well supported but I'd rather have rhizo_1's 'Green Panda' bamboo, Fargesia rufa for screens. Perfect height and bamboos are very pliable. Love the sound of their leaves rustling in the wind, too. :-)

peace_rose - I have 6ft blueberries in that size container. The one drawback for standalone use with tall plants is stability in the wind. So if you can find a way to stablize the pots if the area gets alot of wind (I do it by grouping), then you are good to go.