In a large stockpot, bring the vegetable broth to a boil. Add the carrots, parsnip, celery, onion, and potatoes, return to a boil, and then simmer for 30 minutes or until potatoes are tender. Remove from heat and use an immersion blender to puree the soup. (If you don't have an immersion blender, carefully pour the soup mixture into a food processor, puree, and then return to the stockpot.)

Return the soup to the heat, bring to a slow boil, add the corn, and simmer for another 20 minutes, or until the corn is very tender and the flavor has permeated the soup. Add 1 teaspoon of salt (more or less to taste).