Bush chewer

EugeneT

I realize he probably does it from being bored

That's the problem.  Either fence off an area for your dog so he can't gain access to your plants or consider leaving him in the house during the day.  Leave him a frozen Kong toy or some other long lasting chew that will keep him occupied while he waits for you to get home from work. 

If he absolutely has to stay outside while you are away, can you make him a dog run ?

A 6 ft high good-sized one (so he has room to eliminate away from his rest area) on a concrete pad with a roof , a dog house, partially decked so he can lay off the concrete, a big water dish attached and some indestructible toys would protect both your plants from destruction and your dog from ever escaping the yard.

Keep the dog inside and give him something more entertaining than plants to chew on, like stuffed Kongs.

 Boredom. But if he must be outside, can you "fence" in the plants? So he can't seek and destroy.

 I would have to fence off every single plant separately somehow.

Because of the layout of the house i really do not see how i can fence a piece of the property for him. doggie door takes him out on a LARGE flagstoned area, nowhere near places where he poops or pee. And he has a bunch of toys and i never forget to place them on the floor for him to play with. 

I think he just can not understand that he should not as no one ever there to school him and somehow he never does that when we are home. 

 He no longer does it at home because you correct him when he does it in your presence - he knows that chewing bush + owner home = Bad Things For Dogs, but that chewing bush + no owner present = Good Things For Dogs. Your corrections have suppressed his behavior (and you've probably encouraged an incompatible behavior in it's place, like chewing on his own toys), but it has not traveled over to when no one is present. To him, it's two completely different situations with two completely different sets of rules.

Why can you not keep him inside? Why can you not close off his doggy door? If you must leave him outside, why can you not be a 6'x12'x6' dog run to keep him in?

It sounds like 1. he's bored and needs more physical and mental stimulation when you are present. You need to get his brain and body working, and working HARD when you are home. He needs hard physical and cardiovascular exercise before he's left alone. A tired dog is a good dog, and he cannot eat shrubs if he's choosing to sleep instead. Also, being worn out mentally does wonders as well. So keep him thinking by teaching him tricks and other cues, and by giving him interactive dog toys, like Kongs, Buster Cubes, and other similar toys. and 2. He needs to be confined away from he bushes so he can no longer perform the behavior. Prevention, prevention, prevention!

 Thank you tenna.

I am pretty sure you are right. Yet, i do not seen much fun in terrorizing poor defenseless plant. But then i am not a dog LOL

Let me answer your questions:

I can keep him inside but he would have to confined for over 8-9 hours. I think it would totally sux for him.  He is confined to a small corner of the house with his kennel in there. So he can go in or out. When it is 115 outside i want him to be able to come inside cool house. And if i build him a run outside it is not large enough and he would not have a place to pee/poop :( It would have to be one majestic structure rivaling Egyptian pyramids in magnitude.

EugeneT

I can keep him inside but he would have to confined for over 8-9 hours. I think it would totally sux for him. 

You would be amazed how many people (like myself) leave their dogs in their kennels for that amount of time and all of them will tell you that their dogs are perfectly fine with it. Most of created dogs just spent the time sleeping which is usually what they do if your are not at home and they are not crated

Not only for the safety of your plants but also for the safety of your own dog, right now the plants might be the target, later on he might start chewing on something that would actually cause harm to him.

 I agree but i refuse to keep anyone confined for such long period of time.

I am more then anything seeking a way to figure out how to teach/train him not to do that bad thing he does. 

EugeneT

I am more then anything seeking a way to figure out how to teach/train him not to do that bad thing he does. 

The problem you have is classic and it involves the concept of reinforcement.  Your dog doesn't chew on the plants when you are home and observing because you are there to stop him and correct him.  BUT since he has had many opportunities to chew uncorrected by you the behavior is still getting reinforced every time he chews.   Some behaviors are self rewarding.  Bored=chew=reward and relief from boredom.   Jump fence=freedom=reward.  Steal food off counter=yummy=reward.  That's why no one is able to tell you how to teach him to stop this behavior. 

Your belief that confining him is somehow bad is a common one but it's not founded in the reality of how dogs get along during the day when crated.  It's much kinder to give him a safe place to hang out where he can't get into mischief or come to harm while you aren't home.