Hi! We are also in central OK, and bought a house with an existing pool and landscaping. One thing we have learned is that it doesn't really matter how pool-friendly your own landscaping is, every tree on the whole block will send its leaves blowing into your pool! :) Oklahoma wind is a four letter word in my backyard. LOL.

Our whole backyard is covered in bamboo, and while it's certainly tropical, I never would recommend it. It is the biggest PITA to try and beat back and comes up everywhere: our lawn, flower beds, and in the neighbor's yards, etc. Doing some kind of containment is possible, especially if you do it before you plant the bamboo (if you are really interested, there is a Garden Web Bamboo forum and you can also google Bamboo Rhizome Barrier to see the process). There are types that do not spread that may be able to be planted in a huge container.

We also "softened" the huge concrete pool deck with lots of potted plants - mostly hibiscus, cannas, lime sweet potato vines and palms. These were great. I've got the pots with hibiscus, cannas and palms in my garage right now. My husband doesn't care for this plan. :) Rule of thumb for container plants are to add a zone, so our zone 7 cannas in pots are more like zone 8, meaning they need protection in our winter. You can also dig holes and bury the pots in the ground and mulch over if your garage is full.

For perennials, I can definitely recommend cannas for around the pool in ground, especially if you have a less-windy site that will keep the leaves from getting whipped. They come in tons of flower colors and leaf colors and look really tropical, and are full-sun lovers. Will survive in ground, especially if you mulch heavily, over the winter. Rose Mallow plants are like hardy hibiscus with dinner-plate sized flowers. Some people like Banana trees, I have a neighbor that let theirs get frosted so it dies back but I think they come back every year. Some people dig them and put them in the garage/inside over winter - google hardy banana tree for options.

For some evergreen items to go around the pool and build the framework for the landscaping, a semi-tropical looking shrub might be nandina. They are not too messy, and there are tons of varieties out - I see them a lot at Home Depot with their Southern Living collection.

Hope some of these suggestions help!