Plants for sunny tubs that don't get much water

[Ilovemyshed]

I've a couple of tubs at the front of my house with small olive trees in. What can I plant around the bottom to give some late summer/Autumn colour that will cope with hot dry conditions.

Mesembryanthemum?

Erigeron/mexican fleabane?

Geraniums. Mine have lasted years in a pot by the front door and flower all through the year.

Osteospermum do well in my south facing planters. Regularly dead headed, they go on for ever!

Pelargoniums