, Research Paper
To many people’s surprise, the Venus flytrap is not native to some tropical, exotic country or steamy rainforest. The Venus flytrap is native only to the coast of North and South Carolina, in a radius roughly 100 miles around Wilmington.
It is a small rosette plant, generally six to eight inches in diameter. The leaves consist of leaf stems, or petrels, that may be heart-shaped and flat on the ground, or thin and upright. The trap is the actual true leaf, and sits at the end of the petrel. The traps lure insects by nectar, secreted by glands at the base of the spinney celia, or “teeth”. Inside of the trap are 6 to 8 tiny trigger hairs. An insect needs to touch two hairs once or one hair twice in order to spring the trap. The trap will close in less than a second, in ideal conditions, and if an insect is caught, the trap will seal shut and start secreting digestive juices. If the trap closes empty, it will slowly open in about a day. It may take a week to digest a housefly, and when the trap reopens, the shriveled shell of the insect is left behind. A trap may catch and digest up to three insects, after which the leaf turns black. Older leaves blacken and die regardless of how many insects are caught and the plant continually sends out new leaves during the growing season.
Venus flytraps usually grow along the dampish edges of sandy, wet bogs or fens. The plant begins its growth each spring, sending out a resette of small leaves. Usually the plant flowers around April or May. Summer arrives and the plant produces its larger leaves, often on upright petrels. Some plants remain rosetted all season. With the approach of autumn, flytraps get small. In winter they are dormant, with tiny leaves or no leaves at all. In their native habitat, Venus flytraps enjoy a warm and humid summer, and winters are chilly, with occasional extreme lows down to near 10 degrees F and sometimes lower. From seed, it may take a flytrap 4 to 6 years to reach maturity. They may live several decades.
Venus flytraps grow best in plastic pots. A 4 inch pot is fine for one flytrap. Five to ten plants will grow well in 6 to 8 inch pots. Cover the holes at the bottom of the pot with plastic screen or some long-fibered sphagnum moss, to hold in the soil. The soil itself should be a well-mixed recipe of 1/2 sphagnum peat moss and 1/2 horticultural sand.
Set the pot in a large saucer. To water the plant, it is easiest to simply add water into the saucer than watering the plant overhead. Try to maintain at least an inch or so of water in the saucer all of the time. When the water has just about evaporated, add more. The soil must be kept damp to wet at all times. If you go away on a holiday, there is no harm in raising the water level to the top of the pot to assure your plant won’t dry out before you
return. But flytraps don’t like a permanently high water-table, unlike plants like Sarracenia, which can thrive almost flooded. Flytraps can rot if constantly waterlogged in an undrained container.
Most tap and well water contain too many minerals to be used for Venus flytraps. It is therefore best to collect rainwater for your plant, or use purified water such as distilled, deionized or reverse-osmosis water. We have heard of good results using inexpensive “Brita”-type water filters. Avoid bottled “drinking” water, unless it is specifically labeled “low-sodium”. Allowing tap water to sit a day or two will only allow chlorine to dissipate, leaving minerals behind, so stick with the purified water. Never fertilize your Venus flytraps!
Flytraps enjoy being grown in a partly sunny area. This means that during the growing season the plant should receive about 3 to 6 hours of direct sun. Shade-grown flytraps will appear elongated, with underdeveloped traps. If you live in a climate with cool winters of light frost, your plants will do best outdoors year ’round. If you live in a climate of very cold and snowy winters, grow your plants outdoors from late spring until early autumn. Then move your plant to a bright but sunless window in the coldest room of your house, so it can have a 2 to 4 month chilly dormancy. Never place a flytrap on a sunny, south-facing windowsill for winter dormancy. Flytraps do reasonably well on sunny windowsills during the growing season (March through October), but follow the above directions for winter dormancy.
If you wish to grow flytraps in a terrarium, it is best to keep the plants in pots for easy removal for their winter dormancy. Fluorescent grow lights should be 6 to 10 inches above the plant and on a 12 to 14 hour photoperiod. Remove them in winter to a cold windowsill or outdoors. Flytraps will not survive well year ’round in warm, tropical terrariums. Flytraps love greenhouses, provided they are allowed to have cool winters with nights below 50 degrees F. The plants will eventually die if grown permanently in tropical hothouses.
After 2 or 3 years, flytraps decline if the medium is not changed. Therefore, it is best to transplant them to new soil every couple of years. Transplanting is best done at the end of dormancy, from February to about April. Venus flytraps will catch their own insects when grown outdoors. In insect-free locations, you may feed your plants bugs such as sow or pill bugs, spiders, flies, etc. Dried insects from petshops work well. For healthy plants, during the growing season allow at least one trap to be feeding at any given time, or a minimum of 2 to 4 insects per month. Don’t feed them hamburger, which may rot the traps and invite fungus and mold.
Flowering can have a negative effect on these plants in cultivation, as it will take a few months for large traps to return. Therefore, clip off flower stalks when they are 2 to 4 inches high for vigorous summer leaves. Finally, insect pests do attack these plants, particularly aphids. Check deformed leaves closely: they are usually the result of aphids sucking juices from new leaves. Apply diazinon or orthene. The Lily Miller brands available at K-Mart work well, or use a wettable powder.