Chop the onion, celery, and potatoes and place them in the bottom of the slow cooker.
Add the diced ham and cubed kielbasa on top of the vegetables.
Rinse and drain the white beans, then add them to the slow cooker.
Sprinkle in the garlic, thyme, Italian seasoning, salt, and pepper.
Pour the chicken broth over everything.
Cover and cook on low for 6–8 hours.
About 30 minutes before serving, stir in the chopped kale. (If you are using frozen, make sure the kale is thawed and drained.)
Replace the lid and allow the kale to wilt into the soup before serving.