It looks like your in Alabama, so I'm making suggestions that I think will overwinter for you and are fast-growing.

You could use tall canna and other tropicals like colocasia (elephant ears) and hedychium (ginger) since all like moist conditions and grow to 6 feet. If you get a lot of frost in winter, you can move those in a garage or shed to overwinter or cut them back after the first frost and mulch heavily. These work well using a "stock tank" for a big pot. If your ground is moist (and not from salt water pool), you can just grow these in the ground.

Clumping bamboo (fargesia) is another good container plant that grows quickly, but it's a bit more expensive.

Buddleia will probably do fine with a half-day of sun, but they can take the heat of full sun. 'Royal Red' grows very quickly up and wide. 'Pink Delight' is another fast-growing, full buddleia. Those are drought-tolerant.

Ornamental grasses such as panicum and miscanthus varieties will also work, but will have to be cut back in late winter and then regrow. I don't know when you open your pool (we open ours in mid-May).

If you want evergreens (and have no deer problem), arborvitae may work.

For deer-resistant evergreens, try cryptomeria 'Black Dragon' -- some of the cryptomeria can get quite tall (40-60 feet), so look for a variety that fits your height requirement. Those are slow growers, so you can add ornamental grasses to the mix.

I'm sure I can think of many more ideas. These are just a few that come to mind.

Cameron (North Carolina)