Cook and stir ground turkey, sausage, bell pepper, onion, and celery in a large pot over medium-high heat until meat is no longer pink and vegetables are tender, 10 to 12 minutes.
Stir tomatoes, zucchini, chicken broth, Italian seasoning, sea salt, tarragon, garlic powder, and black pepper into turkey mixture; bring to a boil, reduce heat to low, and simmer until flavors combine, about 1 hour. Ladle soup into bowls and garnish with Parmesan cheese.