What the fence will do is keep those passerbys from snitching from your garden--namely the teens looking for a prank. If you are going to mix in flowers I wouldn't plant in rows but instead plant like you would do a flower bed with small patches of veggies. This will help foil the bugs too. Not slugs and earwigs--they're everywhere--but bugs that prey on specific plants. I read once that if you plant carrots in a flowerbed the carrot rust fly won't be as likely to spot them. If it's going to be wide don't forget the stepping stones.