13 plants that could kill you. mother nature network. April 13, 2010. Over the millennia, people have learned through trial and error which plants are good to eat and which are best to avoid. In our modern, urban world, much of that cultural knowledge has been forgotten. Many gardeners may be surprised to discover that they are growing some of the world’s deadliest plants in their own backyards. Here are 13 plants with lethal tendancies. (Text: Bryan Nelson)