Anne Lurie wrote:

My suggestion so far: Hosta! As far as I know, dogs don't eat it, and it
seems fairly hardy -- although I might have a better idea after it comes
up again.

My dog eats the young hostas when they're first emerging. She bites at
them until they are all the way down to the ground. If I can get them up
a ways then she'll leave them alone. Even the ones that get ripped to
shreds eventually will make it. She's a retriever as well.