Add the canned whole tomatoes to the slow cooker. Using a potato masher, crush them into pieces; you'll want to leave some nice chunks of tomato. If you don't have a potato masher you can break the tomatoes apart with clean hands.
Add everything else BUT the fresh herbs and lemon zest.
Cook on HIGH for 4 hours or LOW for 6 hours, stir at least once halfway through cooking.
When done, stir in the fresh parsley, fresh basil, fresh oregano, and lemon zest. Season to taste.
Serve immediately with spaghetti or your favorite pasta, garnish with more fresh parsley or basil. Enjoy!