Venus Flytraps (Dionaea muscipula) may look exotic, but these carnivorous plants are actually native to the eastern United States. Flytraps, which grow in U.S. Department of Agriculture zones 6 through 8, prefer boggy environments and constantly moist soil. High humidity is a necessity for Venus Flytraps. If the humidity level drops too low, your plant may stop growing or die. You can keep your plant happy by regularly monitoring and raising the humidity level in your home as needed.
Indoors, it's rarely humid enough for a Venus Flytrap to live longer than a few weeks. According to Floridata, though, these plants can live for up to 20 years in the right conditions. Venus Flytraps grow natively in bogs, where they are used to high humidity levels year-round. Flytraps require at least 80 to 85 percent humidity to thrive, although they may survive if the humidity level drops slightly below this. Do not let the humidity level go below 55 percent. Venus Flytraps can't survive for long at a humidity level that low.
Whether you keep your Venus Flytrap indoors or outside in your garden, it's helpful to know the relative humidity level surrounding your plant. An inexpensive device, called a hygrometer or humidity sensor, measures the humidity level quickly and accurately. Electronic hygrometers cost between $15 and $60, depending on the brand and model. Look for a hygrometer online or in your local garden center or hardware store. Set the hygrometer close to your plant for the most accurate reading. If you keep the Venus Flytrap in a tank or terrarium, place the hygrometer inside the container next to the plant.
If it's too hot and dry for your plant outdoors, consider bringing it inside, where you can better control the temperature and humidity level. Running a humidifier is one of the easiest ways to raise humidity in a room. It's an ideal solution if you live in a very dry climate. Boiling pots of water also releases moisture into the air, but this is not always so practical or safe.
You should also keep the plant in a domed container or covered tank as often as possible. Place dishes of water next to the plant inside the tank to raise the humidity level.
Grow your Venus Flytrap in a non-draining container. Unlike many other house plants, this plant needs a swampy, moist environment to thrive, so keep the soil damp at all times. When you water, use rainwater or distilled water only. Tap water may contain harsh chemicals that can harm the plant and it also lowers the acidity of the soil.
Flytraps don't need any fertilizer and they do best in nutrient-poor soil. This is because they catch their own food -- the insects they capture provide all the nutrients they need.