University of Vermont Extension 
Department of Plant and Soil Science

Fall Article

Man-eating Plants?

By Dr. Leonard Perry, Extension Professor
University of Vermont

A favorite scene of Grade B filmmakers is the man-eating plant attempting to devour the lovely heroine. She always survives, rescued in the nick of time by the fearless, handsome hero.

While that makes for a good story line, in reality, man-eating or carnivorous plants prefer a steady diet of insects. And, to add even more insult to moviemakers' dreams, you can grow a carnivorous plant right in your own home, without the fear of being eaten alive or losing a favorite pet.

These curious plants with names like Venus flytrap, pitcher plant, and sundew derive the nitrogen that they need to grow from the bodies of insects that they trap and digest. They grow in wet, acidic soil, which is lacking in nitrogen.

In order to supplement their diet, carnivorous plants have developed a variety of ingenious mechanisms to lure and capture unwary insects. About 40 such plant species are found in this country.

Among the carnivorous plants native to Vermont is the sundew, which can be found in boggy areas. The leaves of the sundew are rounded and covered with red tentacles, each topped with a drop of sticky, sweet-smelling fluid. Insects are attracted by the smell and become stuck in the fluid, allowing the tentacles to close. Gradually, the plant digests the insect.

Many carnivorous plants can be grown indoors at home. You can find them at nurseries and garden centers specializing in unusual plants or through gardening catalogs. Never pick or dig carnivorous plants growing in the wild since many of them are on the protected list. You also need to check with the nursery or mail-order house to make sure their plants are nursery-grown and not from the wild.

The most common carnivorous plant grown indoors is the Venus flytrap. This plant forms a rosette of clamshell-shaped traps on stalks about six inches high. Inside the trap are two blades fringed with long hairs. Insects attracted by the sweet nectar brush against the hairs, causing the lobes to clamp shut, trapping the insect inside.

Carnivorous plants are easy to care for in your home. They do need lots of moisture, and the environment in a terrarium comes the closest to simulating the warm, humid conditions of their native habitats.

Place the plants in a mixture of long-fibered sphagnum moss and sand. Soak the moss in water first for 30 minutes. Place a two- to six-inch layer of the damp moss on the bottom of the terrarium and gently insert the plant, taking care not to damage the delicate root system.

Sprinkle water lightly around the plant, but avoid wetting the foliage. Keep the moss moist at all times. Plants require plenty of light, either from a sunny window or from fluorescent lighting. However, if placed in sunlight, be sure the terrarium is not covered or the plants inside will bake and die. While a nice finale for a horror movie, that's probably not the ending you want your plants to face.

Don't worry about fertilizing your carnivorous plants. Instead, give the plants small insects such as gnats or flies about once a month during the growing season. Or, alternatively, you can feed them tiny specks of ground meat.

During the winter rest period, the plants will require no food (insects), but do prefer cooler temperatures in the range of 40 to 50 degrees F.

Return to Perry's Perennial Pages, Articles