Well, I don't let them eat my Oregano, although I am not sure that they would like it!
Add a post on dandelions if you would like!
https://www.backyardchickens.com/threads/eating-smart-regardless-of-how-you-classify-your-style.1586587/
Grass is good, ducks eat it too!
My ducks sure took care of the dandelion problem!
Hopefully you can get the water you're going to need. First the water goes into the duck pool, next it goes to the garden.