Soak barley overnight in distilled water.
The next day, rinse the barley in hot water and drain well.
In a large pot, combine the soaked barley, grated carrots, grated yellow squash, chopped celery, chopped scallions, minced parsley, carrot juice, and distilled water.
Heat the soup mixture slightly over medium heat, stirring occasionally, until heated through.
This should take about 5-7 minutes.
Serve the harvest barley garden soup immediately.