Cut a circle in the top of your bread, about 2 inches deep. Save the cut out for dipping.
Add the potatoes, celery, carrots, onions, garlic, bacon, broth, ranch seasoning, salt, and pepper to taste to the slow cooker. Stir.
Cook on high for 3-4 hours or on low for 6-7 hours. Add the sour cream and half and half.
Stir until the soup thickens, then pour into the bread bowls.