Chop tomatoes and tomatillos and place in an 8-quart pot.
Bring to a boil over medium-high heat. Cook until tender, about 10 minutes. Stir frequently, and if necessary, spoon off excess juice to leave about half a pot of pulp.
While tomatoes are cooking, chop the peppers and add them to the mixture, since they take longer to cook than the onions.
When the peppers and chopped and added, chop the onions and mince the garlic, then add to the mixture.
Reduce heat to medium. Add the rest of the ingredients and bring back to a boil. Cook until peppers are tender, stirring often.
Pour salsa into pint jars, leaving 1/2 inch of headspace.
Process the jars in a pressure canner for 10 minutes at 15 pounds of pressure.