If you allow your rabbits to run around in your garden freely you should be aware of what they may come across that they will eat. Can rabbits eat dandelions in your garden for example? Dandelions are common in the summer and can sprout up very quickly, they are very common in the wild too so they are not foreign to rabbits.
Dandelions are safe for rabbits to eat. Apparently they must be quite tasty too because my rabbits eat them up pretty quickly. The obvious consideration here is if there are any pesticides or other chemicals that may be harmful. But if it’s in your own garden you should know exactly what you’re spraying around.
Leaving your bunnies to run around your garden isn’t a solution to giving them a little feed either. You should have plenty of Timothy hay available in their hutch, and some pellets and vegetables. They will graze on other things as they see fit to treat themselves to some new and interesting tastes.