Place all chopped vegetables into the slow cooker, spreading them out evenly.
Pour the vegetable broth over the vegetables, ensuring they are mostly submerged.
Add minced garlic, olive oil, dried thyme, and a pinch of salt and pepper to the slow cooker. Give everything a gentle stir to combine the flavors.
Cover the slow cooker with its lid and set it to cook on low for about 6 hours, until the vegetables are tender and fragrant.
Once cooking is complete, use an immersion blender to gently purée the soup directly in the slow cooker until smooth or slightly chunky, based on preference.
Taste the soup and adjust seasoning with additional salt and pepper if needed. Give it a final stir.
Ladle the hot, thickened soup into bowls and serve immediately, enjoying the vibrant colors and comforting aroma of the seasonal vegetables.