I agree with the idea of making a swath of grass/path following your existing shapes, and gardening the rest of the space. I also agree with a brick or stone edging. Both those things worked very well for me. I don't have a sidewalk on the outer edge; my constraint is a deep ditch, which forms the outer limit of the garden space. I like the relatively straight line it makes as the edge. You don't have to do it all at once - start with Yard Advisor's corner bed. Get that set up and planted and keep thinking about the rest. Over the following year - or two or three..., you can gradually extend the corner bed towards the house bed, and along the sidewalk. If you do it gradually, it won't feel like such a big change/lot of work but rather like a natural evolution for the space. That's the way I did mine. Initially, I created a big bed in front and a narrow one along the driveway. A couple of years later, a small one was added behind the driveway border where the driveway curves plus another small bed was added in the N&E corner of the property. After a couple of years it was clear that all of those needed to be made more coherent and connected. So I measured a consistent distance from the edge of the main, large bed to eastablish the ribbon of grassy path that ties it all together. The ditch limited the outer ('moat') bed to a very narrow shape but the brick edge gives it more definition and it all works quite well I think. I think something similar would work well for you as shown in Yard Advisors drawing. Here is a link that might be useful:

A lot of nice plants will take sun in a container if they can get enough water. Can you hook up drip for them or can you water daily? (For many types, that would be morning and evening by hand.) Some old faithfuls that come to mind are red bird of paradise, lantanas of all colors, little john, natal plum, ruellia/dwarf & regular, pygmy palms, weeping yucca, red & yellow yucca...not sure what size you're looking for or if you want to bother keeping plants trimmed back (or want to deal with the litter) but oleander & yellow bells do ok, too. Just mostly depends on how often you're willing to water. To me, lantana, yuccas, ruellia and BoP kept trimmed small looks great in a tropical-like setting and are pretty much furnace proof. I'm sure others will mention other plants, too. Your pond area sounds pretty. Good luck. :)

I have my fingers crossed the websites help you. Someone posted a question to the Texas forum about what tall, narrow evergreens might survive the heat, but I don't think anyone ever figured out a plant small enough for the space described. I think the poster was yearning after the smallish junipers that go next to front doors in magazines... in cooler climates. If memory serves, ligustrum and cherry laurel can be made into topiary, too. Older cultivars of ligustrum can be invasive via seeds, so some people hate it. By the gulf coast, it gets mildewy. On clay in the Dallas area, it seems to be very hardy. It might get too big for your deck, even in pots, though. Ditto with cherry laurel. Your containers should be large enough, definitely. The Container gardening forum has people who know about drip irrigation in containers. Conventional watering in containers is supposed to be done until water runs out the bottom of the containers, and then you let the dirt dry out according to the needs of the plant. I'm not sure how that translates into drip irrigation watering. You can't forget the fertilizer though (like I just did -again-). Hopefully you got the following message directly to your email address, but I'm not sure I've figured how to do that correctly, so here is a resend: The board won't let me post again so soon. Thought of this after the first post. I should have included chinese garlic chives, sweet potatoes, native honeysuckle, iris, day lilies, cannas, rosemary, jujube, and sweet bay. Laurus nobilis, not California Bay. The Herb forum and the Container Gardening forum might be helpful, too. You -don't- want japanese honeysuckle. The yaupons, sweet bay, and rosemary could lend themselves to topiary, similar to your poor, lamented spiral junipers and the ball gardenias. In our area, don't gardenias need morning sun, afternoon shade or light shade all day? They are an acid soil loving plant, so I've never grown them. We have a south facing, full sun back yard, with poorly draining clay full of nutgrass and bermuda .grass. I've been gardening these last years in big yard buckets that hold about 20 gallons of potting soil. Just wait until the nutgrass is gone, then I may make some raised beds! The yard is fenced, so is not as windy as your deck. The containers successfully hold sweet bay, fig, rosemary, jujube, day lilies, chinese chives, yaupon, iris, and cannas in full sun throughout the year. A fig might get beat to smithereens in your location, might not. The containers successfully hold onions, french sorrel, violets, salad burnet, swiss chard, potatoes, sweet potatoes in full to mostly full sun throughout the year or throughout their growing season. I did haul the tubs of plants into the living room during the nasty cold snaps this past winter, otherwise I don't think I've ever done anything special about them during the winter. Hope this helps.

The native Coontie cycad is smaller than sago palms,not sharp, and easier imo I grow them both in full sun and full shade. It sounds perfect for this. A very mature one might be more than 2 feet wide though (but again these grow pretty slowly).... Coral fountain plant might work here and there to tuck into places for flowers+textural interest. I grow some of mine in full shade but they are also a popular plant in Texas approved for full sun xeriscaping. If it weren't for the size limits I'd recc Firebush and Firespikes. I'd say they are containable, would not need more than an annual prune (assuming the Firebush doesn't die back) if their growth rate in Tampa is same as here. Firespikes hate full sun but mine tolerate it surprisingly well, they just will look upset... that's why I like to grow them under my unpruned firebushes (I just annually trim them a lil so they remain shorter than the bushes). Leadwort also probably gets too big but it doesnt mind hot sun nor a lot a shade. Begonia & Impatiens can work in shade but the sun part in the summer might be a dealbreaker without being protected by a larger plant overhead. An attractive large container and some other hardscaping features might help? My container dwarf figs go dormant in my zone 9 yard so they should not mind full shade in winter for example. Also I'd be careful with elephant ear.. they're a pretty nasty invasive species unless you get one of the tamer cultivars. I have a tamer cultivar (Black Coral) and even I keep it in a container, I see so many spread to forests around here.