Cover bottom of large soup pot with 1 inch water. Start heat under pot.
Wash barley in a sieve and transfer to pot--it's good if it cooks for a while before you start adding the veggies.
Wash potatoes and carrots, take eyes out of potatoes and cube and cut carrots into chunks of about the same size. Transfer all this to pot at once. When water starts boiling again, let cook 10 minutes, stirring once.
In the meantime, wash zucchini and cut lengthwise and slice (pieces should be about the same size as carrot pieces). Also chop tofu after washing and draining it. Add these two ingredients at the end of the 10 minutes, and cook 5 minutes more.
Wash and cut up celery and chop garlic to your liking. Add at end of 5 minutes and cook 5 final minutes. Add herbs until it smells really good and let sit 10 minutes or more before serving.
This is adapted from my mother's soup recipe that I learned when I was growing up. I cook a huge pot of this every week and heat it up for lunch or dinner. If you want it to be more interesting still, you can add a spoonful of miso or some nutritional yeast after you heat it up.