Are mole plants poisonous

he Mexican marigold (Tagetes minuta) is a malodorous plant widely used in plant companion for its ability to repel pests. Companion planting is an example of an organic pest control method. And adventurous landscapers seeking mole control the organic way don't have to settle for planting the commonplace marigold. A couple of "living mole repellents" have a decidedly exotic flair: namely, mole plant and Castor bean.