whats squashing my bee baum?

[crash50]

I recently planted four bee baum (I hope I am spelling that right) They lasted about a week. I was thrilled by the humming bird that started to show up. I walked out one morning to find them literally squashed! I ended up having to clip them almost to the ground. It was very sad. I initially thought it was a cat after the humming birds. My neighber says that squirrels like to jump on the plants (this sounded ridiculous to me )Now I just want to know what squashed the bee baum? and how do I protecked the plants in the future? Will I have to wait for next year to see flowers again? I'd really appreciate any advice you can give