
We have a lovely field where our dogs run around in twice a day, it is a lovely natural grass ley with meadow grasses and herbs. My dogs spend a lot of time choosing which variety of grass and herbs they are going to pick and eat and they are never "sick".
I would never stop my dogs from eating grass or herbs, they know which is good and what is needed.
They also love to go blackberry picking in the autunm, they look and pick for themselves but if some are too high I will do the job for them. No other dogs can get into the field.