We're interested in one that grows fast and grows downward to add interest to the outside of our deck fence.

try jasmine, but you will need to plant it in the ground, not on the top of your fence...anyway, you will need some twine for the tendrils to grow up. The plant will cascade down like a waterfall, once it has matured. It has fragrant white flowers that attract humming birds & bees...there's also bougainvillea. Check with your local nursery, as they can help you find just the plant your looking for...

most anything you plant should be planted in the ground - at the very least as a potted plant on your deck.. make sure its a big enough pot. .. i would grow trumpet vine, as it grows 12' per year- morning glories another favorite. .. check with your local nursery, as they can tell you what is good for your area..

happy planting

moonflower is great because it grows quickly, has large, saucer-shaped blooms, and it closes up during the day and blooms out atnight. It's called moonflower because its pale, lavender-white blossoms capture the moonlight and the blooms seem to glow at night. It's really striking.
on another end of the spectrum, you could try trumpet plant; it has brilliant orange, trumpet-shaped flowers that attract hummingbirds. It grows very quickly, but you can control its growth with pruning. has lots of bright green foliage as well.
a rambling red rose is nice too. there are varieties that grow very quickly and are fragrant as well (ask your nursery) .
whiteflowerfarms.com is a great resource. It's located in CT but can help with all kinds of questions for any zone.
I like morning glories, but care must be taken or they will rule the world! Prune!