In a large saucepan cook vegetables in 2 cups vegetable broth until tender, about 45 minutes. Add dill seed.
While vegetables are cooking make sauce as follows: Melt butter in medium saucepan; stir in flour and cook 1 minute, stirring constantly. Stir in milk and remaining 2 cups vegetable broth. Cook over medium heat, stirring occasionally until thickened, about 8-10 minutes.
Add cheese, thyme, and white pepper.
When cheese has melted, add to vegetable mixture and stir well. Add crumbled bacon and stir again.