Greetings, welcome to the Forums.
I like the idea of planters in that corner. You will want large ones. the size of half-barrel planters or larger. Metal or plastic water troughs with drainage holes are another option. You might even consider constructing a permanent raised bed of brick, concrete, wood, etc.
As for what to plant, there are a number of options that will give height. A small tree, a large shrub, a vine on a trellis, bamboo, etc. Before going into specifics, tell us more about what type of plant would you like to see there?