Maintaining container arrangements year around
I live in a mild climate -- SF Bay Area, and believe I am in SS zone 16/17.
I like to keep containers with plant arrangements around my property and my main interest is aesthetic. As an example, I have a mature Sago palm, a japanese maple, a New Zealand Flax grass as the main thrillers in my container and have been able to grow them successfully.
My problem is with spillers. I have been trying several varieties like Calibrachoa, Bacopa, Freesia, Begonia, Fuchsia, Verbena etc. Some of these like Freesia, Fuschia etc are obviously not evergreen but will due care, will come back the season after. (I also have couple of containers with succulents, they always look good -- but I would like to also have some other foliage or flowering arrangements.)
My problem is with the borderline plants for my zone. Most others like Bacopa, Verbena etc are supposedly perennials but they either act like annuals or come back very very weak.
So my question to you great container gurus is, if you have any pretty container arrangements, how do you keep them looking good year around? Also, what sort of plants do you recommend that would keep their beauty all around?
Pictures will be appreciated!