Red foxglove (Digitalis purpurea) is not a harmless plant. All parts of the plant are poisonous and even small amounts, such as eating two leaves, can be fatal to humans.
Snails usually give the bitter-tasting plant a wide berth so as not to come into contact with one of their approximately 100 toxins, the glycosides or digitaloids. Other pests also leave the plant largely alone and it is also not susceptible to diseases. Since the leaves contain not only toxins, but also numerous nutrients and minerals, they can be used as green manure.