Chesapeake bay creamy asparagus soup

Ingredients

• 1 medium potato, peeled and diced
• 1 medium onion, chopped
• 5 green onions, chopped
• 1 medium carrot, chopped
• 1 celery rib, chopped
• 1/4 cup butter, cubed
• 1/4 cup all-purpose flour
• 1 teaspoon salt
• 1/4 teaspoon pepper
• 1 can chicken broth
• 1 pound fresh asparagus
• 1/2 cup half-and-half cream
• 1 cup sour cream
• 2 bacon strips, cooked and crumbled
• Asparagus tips, optional