Have gardened with dogs all my life and with never a concern about the plants in my garden. They have never showed any interest in eating or even chewing on any of them. Puppies that like to dig or chew may be another issue but adult dogs are much smarter than many give them credit for :-) Since I grew many quite toxic plants (much more so than any hydrangea), I was more concerned about my child and the plants but even she while still quite little was easy to train not to put anything from outdoors in her mouth.

The only concern I had gardening with my dogs was to avoid planting something in their immediate travel paths - they like to patrol the fenceline and anything not very substantial in their way would be trampled. And to avoid highly "fragrant" organic supplements like blood or bone meal, which they would immediately root into. I also had one rather dumb dog that made herself sick eating dead slugs (killed using either salt or pet safe Sluggo) but that was only a temporary - and messy - stomach issue :-)

I can vouch on that. I have not had problems with hydrangeas either although all my dogs were not puppies when I got them. No problems with hydrangeas or azaleas. However, I lost some hydrangea plants when my dogs (German Shepherd, Golden Retriever, Border Collie, Lab... all mutts) declared war on squirrels and the plants were on a solid line between the dogs and the squirrels! Hee hee hee! $$ $$ $$. Sniff, sniff.

Mine has only ever eaten vegetables off the vine! I know the harvest is ready when he sneaks in with a jalapeño or a tiny watermelon!

I dog sit for my son, and the dog (part hound) has never shown any interest at all in my garden. She'll munch grass in a wild area close by, but has never touched a hydrangea, and I have tons of them. But ditto what luis said - when the dog is chasing squirrels or chipmunks, plants can get trampled.

And what is that deal with eating grass??? It seems to be related to stomach issues but where did this come from??? I have n-e-v-e-r- seen the dogs read a newspaper that told them to eat grass for stomach problems! Hee hee hee! Just today at 4am-ish... let me stress that again, at 4AM.... I had to take one of the dogs out. She woke me up and went on to eat grass for who knows how long. I almost fell asleep waiting in the sofa. LOL! But I guess, as leader of the pack, I was supposed to do that for her. :o)