I have noticed that dozens of kinds of plants--notably many Colorado alpines like Eritrichium, Phlox condensata and Clematis tenuiloba, only seem to persist in troughs.
As I was scrolling through old images, this picture with Androsace 'Millstream' and a few specimens of Draba polytricha remind me why troughs are de rigeur!
It's been heartening to see how trough gardening has spread among rock gardeners, and increasingly among the general public. We need more articles, more books and a lot more ways to educate people about these portable rock gardens, these glorious little chunks of nature. Maybe we can call them High Definition containers or Broadband gardens to widen their appeal among those poor souls with digital minds and texting fingers.