tl;dr: ideas for how to "bridge" the visual/thematic gap between a cottage style garden and a palm
Hello! I'm in USDA zone 5b and share a large balcony with my neighbor. The balcony is big but unfortunately my only outdoor space. Each summer my neighbor picks up a large palm tree (areca or majesty palm if I had to guess) and plants it in a container on the dividing line where his side and my side of the balcony meet (we each have one half of the deck, though there is no divider between us).
This year I'd like to design my "garden" in a full-on cottage style- container rose, hydrangea, pink and purple and white and soft blue annuals everywhere- the whole deal. However, I don't want to have a harsh juxtaposition between this style and my neighbor's palms. I also don't want to put up a divider between our sides of the deck because our side gets amazing sunsets and I'd feel kinda douchey blocking off his view of those. He's a good dude.
So my question is this: does anyone have any ideas for a "transition" plant or two that I can place physically between his palm(s) and my more traditional cottage garden plants? That way the eye has at least a primer when it wanders between our two sides of the balcony. The plant(s) would receive full sun and will need to survive in a container, though I'm open to perrenials if necessary as I can try to overwinter them in a friend's decently insulated garage. I asked my partner if he could think of any way to blend the cottage style with a tropical style- he responded "you can't", but I refuse to believe that :)
Thanks so much for any ideas!