At the moment your dog is very young and keen to get his teeth on anything, he's just like a two year old child. Don't let your dog dictate what is supposed to happen, you are the responsible one. This type of dog needs a lot discipline, walking on the lead, listening for your commands to educate it. It thinks of the rose bush as a play item because you haven't told it that it isn't, be firm, give your dog other items to play with and reward him when he's good and chastise him when he's done wrong. Try walking with him and another dog walker, dogs learn from each other. Join a dog class when your dog is 6 months old, not before. My dog eventually became my soul mate so don't be in too much of a hurry. Enjoy your dog and love him, he will love you back ten fold.