I don't know what would happen if a dog ate a stomach full of ripe grapes, but they are not toxic. We had an English bulldog that would work for grapes and he lived to be almost 15 years old. I have grape vines encircling a section of my back yard and I have all sorts of dogs coming and going back there every day.Thanks all, I’m going to look for the flowers. I really don’t want to have to manage the gape vine esp if it grows large. Too risky for the dogs…
I can assure you that growing grape vines will not harm your dogs any more than any of these other plants we are talking about. They are a terrific source of tortoise food. I use the leaves as substrate in my brooder boxes for starting hatchlings, and I clip branches to put into all the baby enclosures for them to nibble on and hide in. You are dismissing the best plant for what you are asking for for reasons that are not valid. Grape vines are a huge part of my tortoise keeping strategy, and I don't ever deal with grapes. I think you've got the wrong idea in your imagination and if you give it a try, you will see how easy and beneficial it is.
Another problem with any decorative vine is that all store bought decorative plants are grown with systemic pesticides that last for a year in the plant's tissues and cannot be washed off. That is why I was asking Rosemary about cuttings from her established plant. Because grape vines are intended for human food, they don't come with these nasty systemic pesticides in them.