Are tea plants innately slug-resistant?

An Alaskan gardener suggests using coffee grounds as slug repellent, as slugs apparently hate caffeine.
A Swedish farm already grows tea, and they sell tea seedlings.
As part of our research at Agrikultura, Martian Tea proposes to introduce tea seedlings into one of the gardens in a nearby town which is tormented by black slugs.
Tea may be a source of nutrients to Mars inhabitants should the Martian slug population get out of control and devour many other crops.