One of the most unusual types of perennials you can grow in a garden is the pitcher plant.These plants can be grown most easily in zones 6 through 8, but will adapt to colder zones if protected with a mulch in the winter.There are eight different species of these plants in the U.S., ranging in size from four inches to three feet! They all have one thing in common: They eat bugs.The plants secrete a wonderful smelling nectar (wonderful to the bugs, that is).Once the b...