Plants on the south side of the garden

Maybe grasses like switchgrass can also manage under these conditions. The location fits.
They do well for me in full sun
Switchgrass
Asian bugleweed
Pringle's aster
Bog pipegrass
Foxglove beardgrass
Candelabra speedwell
Echinacea

Make sure to cover the soil with mulch. I think a little is better than nothing and helps prevent drying out

A good tip, thank you very much

why even such small boxes - just use the garden and make it easy for yourself. Honestly - I find, for example, container gardens beautiful, in courtyards or so, each plant in its own little pot, a dreamy eye-catcher. But the work, never. We also have a south garden with a south-facing terrace. I have a raised bed for herbs directly on the terrace, and only the annual chili and tomato cultivation in boxes. Everything else only goes into the bed or then on the north side into the tubs. And I don’t have a full-time job and have plenty of time for the garden - but watering such small containers several times a day, no, that’s too much effort even for me.

Container gardens are wonderful. My flower watering service, for the holiday period, will strike next year if there are not fewer pots. So no container garden.