Carnivorous plants need special care if you grow them in your home. They typically grow in bogs and swamps, and their natural habitat has to be replicated as closely as possible. There are more than 400 species of carnivorous plants worldwide, many of which make suitable houseplants.
There are two groups of carnivorous plants: those with passive traps and those with active traps. In passive traps, the insect simply falls into the plant. In active traps, the plant has to sense the presence of the insect and trap it. The pitcher plant uses an passive trap; the Venus fly trap is an active trap.
Pitcher plants have a thickened rim and lid at the top, which prevents insects from crawling out. Sundews have an elongated leaf that is covered with sticky hairs. The insects get stuck to the hairs and are digested. The Venus fly trap has folded leaves that are hinged in the middle. When the insect enters, the hinge snaps the two halves together, trapping the prey. Bladderworts are aquatic plants. At one end is a flap of tissue that forms a trap door. When the insect lands on the trigger hairs at the bottom of the door, it swings open and allows the insect to enter. The door cannot be opened from the inside and the insect is trapped.
In nature, most carnivorous plants grow in bogs with peaty soil that is highly acidic and water-soaked. Their home terrarium environment has to have a humidity level between 70 and 90 percent. The terrarium should be partially open to promote air circulation, and it should be moved during the day to get as much sunlight as possible. Too much heat will cook the plants, however, so keep them 1 to 2 feet back from windows.
Plant carnivorous plants in a mixture of sphagnum peat moss, medium-grade orchid bark and course builder's sand. Water the mix with distilled water or rainwater until it is saturated, then add another layer of peat moss on top. The plants are added last. Never use tap water--it contains minerals that can build up in the soil and damage the roots.
Do not feed raw meat to a carnivorous plant. They are not meat eaters--they are insectivores. The fat in meat can kill the plant. Do not fertilize carnivorous plants. The soil they live in does not have nutrients, and fertilizer can kill the roots. The plants get their nourishment solely from insects.