Venus fly traps are among the coolest plants you can grow. In their native habitat, Venus fly traps live for years. Unfortunately, they are often short-lived plants in cultivation, but this is only because most people don’t care for them properly. In this article, you’ll learn all the essential basics of Venus fly trap care.
Varieties of Venus fly traps
There is only one species of Venus fly trap, Dionaea muscipula, and it is native to a small region of eastern North and South Carolina. Over the years, it has been bred to exhibit different traits, and there are now dozens of different cultivars on the market. Some of the types of Venus fly traps you may come across include ‘Red Dragon’ which has a dark red coloration, ‘Justina Davis’ which is a solid green, ‘Flaming Lips’ which has bright orange traps, and ‘Purple Haze’ which has deep purple traps, among many others. There are some pretty funky growth forms out there, too, though they are often only available through specialty plant nurseries. Most are propagated via tissue culture, but sadly, wild collecting does still take place, even though it puts native populations in peril.
The majority Venus fly trap varieties grow just an inch or two tall and wide, though some larger cultivars exist.
Venus fly trap care essentials
In order to properly care for a Venus fly trap plant, you first have to understand what it needs. Like other plants, what a fly trap needs to grow is based on where it evolved and what it requires from its natural environment. The same factors you consider when caring for other plants should also be taken into account when it comes to caring for a Venus fly trap. In a nutshell, those factors are light, the growing medium, water, nutrition, and, for Venus fly traps, a special dormancy period. We’ll talk about each of these factors in turn. But first, let’s talk about the fact that Venus fly traps can be grown both indoors and out.
Venus fly trap care: indoors vs. outdoors
Venus fly traps are significantly easier to care for when grown outside as a winter-tender plant, rather than growing them indoors. Home environments aren’t ideal, unless you have a very bright window and can give the plants a lot of attention. However, I’ll discuss both indoor and outdoor Venus fly trap care in this article because I know that not everyone has the ability or space to grow them outdoors.
The best planting mix for Venus fly trap plants
Regardless of whether you decide to grow your fly trap indoors or out, you’ll need to consider the best growing medium to use first. Venus fly traps evolved in the very lean, low-nutrient soils of bogs. That’s why they developed the interesting adaptation of relying on nutrients absorbed from their insect prey, rather than from the soil.
Do not plant Venus fly traps in garden soil or in regular potting soil. Instead, use a mix containing two parts peat moss and one part perlite. An alternative mix is a 50/50 blend of peat moss and perlite. Pure high-quality long-fiber sphagnum is a third option.
The best light levels for Venus fly traps
These carnivorous plants require a lot of sun. If you’re growing your plant outdoors, 4 or more hours of direct sun followed by 2-4 hours of indirect sun is best. Indoors, a south-facing window that receives at least 6 hours of full sun is necessary if you live in the northern hemisphere. Alternatively, put the plant under a grow light for 10-12 hours per day during the growing season. Choose a light system that produces light in the blue wavelength and place the lights about 6 to 8 inches above the plant tops.
Do Venus fly traps need to be in a terrarium?
Contrary to popular belief, you don’t have to grow indoor Venus fly traps in a terrarium. In fact, fully closed terrariums can cause the plants to develop rot. If you have an open-topped terrarium, fly traps should do fine. It’s just enough shelter to keep the humidity around the plant high, but not so much that it causes rot. Never grow fly traps in a terrarium outdoors, however, because the glass amplifies the sun which often leads to leaf burn.
How to water a Venus fly trap
Indoors or out, keep the growing medium moist to wet at all times. Remember, these are bog plants. Do not allow the soil to dry out. Water the plant by sitting the base of the pot in a saucer of water for a few hours at a time every few days. Some growers leave the pot sitting in a saucer with a half inch of water in it at all times, but I find this increases the risk of rot. If you’re growing a fly trap outdoors, to keep the roots from becoming too hot on the hottest days of summer, add cool water to the saucer on a daily basis.
Use distilled or rainwater only to water Venus fly traps. They do not tolerate water with chlorine, dissolved minerals, or salts in it. This is very important.
How to feed a Venus fly trap
If you grow your fly traps outdoors, they catch plenty of prey all on their own, but if you’re growing them indoors, you can catch flies or other garden insects in a net and use a pair of terrarium tweezers to feed the bug to your plant.
Inside each of the traps are a handful of trigger hairs. If the movement of an insect hits the same hair twice within a few seconds or two different hairs are tapped in quick succession, the trap is triggered to close. Digestive enzymes are then released by the insect’s continued movement after the trap has been triggered, and the plant is able to absorb the nutrients contained in the insect. Feeding a Venus fly trap in this way is not necessary, but it sure is fun!
A few don’ts when it comes to feeding bugs to a Venus fly trap:
- Never feed your plant prey during winter dormancy (more on this in a bit).
- Do not feed your plant hamburger or any other meat. It’s not able to digest it since the enzymes are only released by movement that takes place after the trap has closed.
- Do not feed your plants more than one or two bugs per month.
Fertilizer for Venus fly trap care
Since fly traps live in lean soils, there’s no need to add supplemental fertilizer. They do not like compost, or granular or liquid fertilizers. In most cases, fertilizing kills them.
How often should you repot a Venus fly trap?
Repot Venus fly traps every year or two, selecting a slightly larger pot and changing the growing medium each time. The best time to repot a fly trap is in the early spring.
Venus fly trap care in winter – dormancy is essential!
When autumn arrives, Venus fly trap plants begin to shift into a natural state of dormancy. They stop growing and most of the leaves turn black and die. The mechanism that triggers any remaining traps to close no longer works. This is your signal that the plant is shifting into its winter dormancy. This dormancy period is absolutely necessary and lasts 3 or 4 months. Remember, your plant is not dead. Don’t throw it away; just change how you care for it.
Dormancy is triggered by the shorter days and dropping temperatures of autumn. It’s nothing to panic about, I promise. Trying to fight this natural dormancy period spells death for your plant, so don’t ignore it. Plants need it, regardless of whether they are growing indoors or out.
Regardless of whether you grow your plant indoors or out, put it in a cool location, such as an unheated attached garage or a cool basement, for the dormancy period. The plant doesn’t need much light, but close to a window is best. Venus fly traps can survive occasional winter temperatures as low as 20°F in the wild, but in a container, they aren’t quite as hardy. Winter dormancy temperatures that hover between 50° and 35°F are ideal. If you live in a region where the outdoor temperatures don’t drop lower than 30°F, there’s no need to move the plant into a garage; just leave it outdoors through the dormancy period.
Let all the leaves turn black and die. The plant is resting. During winter dormancy, be sure the plant is kept moist at all times. Do not feed your plant and do not fuss with it. Just let it be.
When spring arrives, the temperatures rise into the 50s, and the days lengthen, move your plants back into your living space if you’re growing them indoors. Or, put them back on a sunny patio if you’re growing them outdoors. If there are any dead leaves clinging to the plant, now is the time to cut them off.
Venus fly trap care basics
As you can see, caring for Venus fly traps correctly is the perfect combination of art and science. They are truly fascinating plants that deserve a home with any gardener willing to let them have their winter rest.
Need more care advice for carnivorous plants? I recommend The Savage Garden by Peter D’Amato.