New gardeners are often dismayed at the quick decline and death of a Venus flytrap purchased in a healthy state from a garden center. Carnivorous plants often have very specific needs, and are adapted to an extremely narrow range of habitat. The key to successfully growing them involves mimicking their native climate as closely as possible.
Dionaea muscipula is the most common variety sold, and the easiest to grow. This is a very small plant, usually only growing about 6 inches tall. Plants have an abundance of green traps with reddish interiors. This flytrap species requires a cold period in which to go dormant. Without it, the plant will eventually die.
Dionaea muscipula is native to the southeastern United States, where temperatures are cold enough to cause dormancy, but there are no prolonged freezes.
Occasionally, some tropical species are available for sale. These have rather exacting growth requirements and should only be grown by experienced gardeners. Although these species do well indoors, each type has different needs and should be researched thoroughly before an investment is made.
Dionaea muscipula grows best in a media composed of one part sand and one part peat moss, well mixed. Fertilizing these plants is completely unnecessary and may actually cause disease or death. Using chlorinated water on carnivorous plants is almost always the cause of a sudden decline in health. Flytraps do their best when watered with rain water or distilled water.
Dionaea requires a lengthy cold period in which it can go dormant. Growing them outdoors in a bog garden or a pot is an easy way to provide this. In very cold climates, bring them indoors after the first fall frosts, and stored in a cool area that does not freeze.
Feeding flytraps grown outside is usually not needed. They manage to catch their own insect supply quite handily. Indoor specimens may occasionally need a dead fly, spider, or cricket. Teasing the flytrap to close without feeding it is a good way to kill the plant. In general, wait to feed the flytrap until all of the traps are fully open.
Dionaea muscipula is only reliably cold hardy in zones 7 through 10. In colder areas, the plants can be grown in a container, or potted up for the winter and moved to a cool location indoors. After the foliage dies back in fall, place them in a sheltered area.
These plants absolutely need a dormant period of three to five months for them to survive and continue growing through the years. During this dormant period, cut down on watering plants stored inside. Hardiness of outdoor plants can be increased by applying a thick coat of mulch such as pine or fir needles. The most important thing is to keep the roots from freezing. Even though the top of the plant may look quite dead come spring, they will quickly show new growth when warm days return.
The diminutive size of the flytrap really requires that it be grown in a area where it can be easily seen. Locating a small bog garden off an existing pond is one way, as is constructing a small bog near a patio or sitting area.
A homemade bog garden can be as simple as a rough hole lined with plastic and filled with a mixture of peat moss and sand. Flytraps should be grown on their own in the bog garden. Other bog plants have far more aggressive growth habits, and can easily dominate the tiny and slow growing flytrap.
Containers are a wonderful way to enjoy flytraps up close, and they make winter storage very easy. Pots with drainage holes can be lined with plastic, and filled with a mixture of peat moss and sand.
A few small holes punched in the plastic will provide the perfect balance of moisture retention and drainage. Places with hot and dry summers lack the humidity these plants need. A tray or saucer placed beneath the pot and periodically filled with water will help maintain moisture levels in the air.
Most problems stem from irrigating with chlorinated water and not providing a dormant period. Flytraps are often inadvertently killed by 'teasing' the traps to close. This forces the plant to go into a growth spurt, without the nutrition an actual insect in the trap would provide. Doing this too often will definitely kill the plant.
Forgetting to water a small potted plant on a hot windowsill will also cause death. Flytraps need a steady, even amount of water. Allowing the plant to dry out, even for a day or two, will most often result in death.