Trish, have tried pots embedded in soil, but only for yellow loosestrife.
They didn't do the job for me either.
We must be lucky; only see/notice rabbit damage to bulbs in earlier spring. None later.
My feeling is that learning to manage perennials is an on-going learning thing!
There are certainly some great and well-behaved campanula. I especially like the big ones, e.g. Campanula latifolia 'Brantwood' below (June 21, 2014).
