The white plants would be very nice in a winter theme garden, especially the tree. The black tree would look good in a haunted theme garden. The black cactus doesn't look so good and the black snowdrops are hard to see on grass/soil.
I think the white hops are really nice and would also look good in both bright and dark red, pink and maybe yellow, orange and magenta too.
Would be nice to have some of the smaller hops in the future too along with the untrimmed hedges.