Lab boxer mix chews everything

Question
I have a 7 month old lab boxer mix and everytime we put him in the back yard by himself he whine constantly and he chews up everything in the back yard, I.e. table cloths lawn furniture trampoline and various other things. He is completely destroying our back yard and cannot be left alone even for five minutes without destroying everything in sight. I am not sure what exactly to do and am looking for some good honest knowledgeable help. He also digs huge holes everywhere in the yard and I can't get him to stop. Any help would be appreciated.

Answer
All adolescent dogs need to chew at that age, so that their adult teeth set correctly into the jaw bone.  Dogs also chew to comfort themselves.  I never advocate leaving a dog alone in a yard.  They hate it, since they are such a social species, and often develop behavior problems related to boredom or fear.  Why not provide your dog with some appropriate chew objects for while he is relaxing in his crate (Kong toy stuffed with his dinner and a bit of yogurt frozen in, or a bully stick)?  When he is outdoors, be out there with him and play fetch with a tennis ball?  Do some training, for mental exercise, as that tires the adolescent dog more than the physical exercise sometimes.  As for the digging, that's really difficult to stop, but one way that my clients have had success is to build a small digging pit or sandbox, fill it with sand or previously dug dirt, and bury a few dog biscuits there.  Help the dog dig them up and make a big deal of finding them.  Periodically bait the area again, and redirect any attempts to dig in other areas of the yard.  Good luck!