The concept of ethical harvesting is really pretty simple: don’t over-harvest. If you find a stand of your favorite wild foods, don’t pick everything available in that location. Leave some there for the animals to eat, other people to gather, and, most importantly, so that the plant can continue to propagate itself in that spot. If you over-harvest, you may deplete the supply and then you won’t have your favorite wild foods there any more.

You can notice an example of that in Garden of the Gods. Wild asparagus, which has likely been over-harvested, is very rare there now, plus you’re competing with the deer and other critters that like to feed on it. So, if you harvest from a spot, leave some there. It’s simple.