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Venus Fly Trap (Dionaea)

Introduction

By far the most famous of the Carnivorous Plant genre and probably responsible for more people getting involved in this type of plant as anything else. It was certainly the reason that I started growing carnivorous plants!
It is the only plant of it's type and is normally found in the Carolina areas of eastern North America.
In fact, according to Carl Stevens, who lives in North Carolina, "the natural distribution is a little more confined than what people may believe. The entire natural distribution of the flytrap is a circle about 75 miles (120km) from Wilmington, N.C. This covers the Southeast part of N.C. and the Northeast part of S.C."
The bogland areas where it normally grows are devoid of the nutrients that it requires, so the plant grows stems which have traps on the end. It is in these traps that the insects are caught.

How it works

A normal plant will grow the stems up to 5 inches (about 13 cm). The trap will consist of two pads which are hinged together on one side only. Along the other edges of the trap are 1/4 inch long spines which stand outward, similar to eyelashes.
The trap mechanism is triggered by three hairs which are inside the pads. If you look very carefully at a pad (it's best to look along the hinge), you will see three tiny hairs sticking out from the middle of the pad. Each and every pad has these hair triggers.
When an insect crawls into the trap, it must touch either two different hairs, or one hair at least twice. Once this happends, the pads close together very fast. As a precaution against false triggering by inanemate objects or rain etc. the trap will reopen if these hairs are not triggered again. If the captured insect continues to struggle, however, the hairs are continually touched and this forces the trap to close even tighter, until a complete seal is made along the unhinged edge. You can see that the spines have now done their job of keeping the insect from escaping, and have turned outward.
It is at this stage that the digestive enzymes are released onto the insect which is slowly eaten away, the nutrients being re-absorbed through the pads themselves.
About 4-5 days later, the trap will re-open, revealing the dried up remains of the insect which would normally be blown away by the wind.
The new influx of nutrients will lead to new stems being produced from the centre of the plant.

The lifecycle of the Venus Fly Trap

During the spring time, the plants can produce a very long thick stem from the centre of the rosette. This stem can grow over 10 inches high and may be topped with small white flowers which flower for a few days before dying off.
The stem itself continues on for a lot longer, however, it can be cut off at the base once it has stopped flowering. The closed heads, if pollenated, may have produced seeds.
The summertime produces the main growth and this continues right through to the autumn when the trap production slows.
In the winter, the plant enters a dormancy stage. Trap production stops or is produced only very slowly. Don't feed the plant during this time.
I'm not sure as to the lifespan of a Venus Fly Trap, however, I have one which is four years old now.

How and where to grow them

• The Venus Fly trap likes as much light as it can get. A south facing windowsill is ideal. The traps grow with red middles if they are getting sufficient light, although completely green traps work just as well!
  
• Grow the plant in live or shredded sphagnum moss or in specially prepared compost that is available in some shops. Never use ordinary compost as this is most likely to contain extra nutrients in the soil which could be enough to kill off your plant!
  
• NEVER give it fertilizer of ANY kind. This will do the plant untold damage since it should get it's nutrients from the insects it catches, not the soil.
  
• Stand the pot in a trough of water, rain water is best, but anything that isn't hard. You should aim to keep about 1/4 to 1/2 inch in the trough at all times, so the soil stays nicely damp.
  However, during the winter, reduce the watering to a minimum, only once every couple of weeks, just so the soil doesn't dry out completely.
  Also, there is no need to water the top of the plant at all, just let the plant soak up the water from the tray.
  
• Resist the temptation to trigger the traps, each closing of the traps will lose the plant some more energy. Obviously, if the plant isn't catching food with these closures, it will slowly get weaker.

• Snip off the rotten, brown leaves as they die away.
  
• If you do feed it DON'T use dead stuff, chicken, steak,flies etc!! This is because the traps need their hairs to be continually triggered for a time to allow the digestive enzymes to be released. Now, obviously, your bit of dead chicked won't keep triggering the hairs on the petals once the trap has closed. The trap will then reopen in a few days, without disolving the food.
  
• If your plant hasn't caught anything reciently and you're getting worried, see if you can catch an alive or semi-alive insect that's still moving about. Drop it into a trap and is should perform the required movement to get itself eaten!
  (I've discovered that fly spray causes the flys in my house to get stunned and fall to the ground. They keep moving, however, for quite a long while, enough time to drop one into a hungry trap!!! I'm not sure if the fly spray affects the plant though, so I never spray near the actual plant. Flys covered in fly spray do not seem to affect my plants, though.)
• If you do get a flower stem grow and the plant is still small (under 4 inches diameter) I would cut is off early, because it will be unlikely that it will flower, and the plant looses too much energy producing the stem.
• These plants can be grown outdoors, especially if you live in warmer climates than here in the UK. However, I have a VFT in the garden at the moment, buried in it's original pot (to maintain the nutrient free compost) and close to a run used by the local ants. When I first planted it, within half an hour, all six of it's current traps had been triggered!
• The temperature must not be allowed to drop below freezing, so I'll have to re-dig up the pot and bring the back indoors before the first frosts arrive in October.
• I know it's unlikely, especially if you keep your VFT indoors, but if your VFT catches greenfly or some other horrible small pest that is too tiny to trigger the traps. Greenfly can be a big pest. You notice a greenfly attack when the new leaves start growing all twisted and deformed.
  You can get rid of them by either buying another type of carniverous plant, something like a Sundew, which has sticky petals and will mop up the greenfly if it's planted close to the VFT. Or you can submerge your VFT completely underwater (soft water, mind) for 3 or 4 days. This won't affect the plant in the slightest, and will hopefully drown the greenfly!
  I have used an indoor insecticide sprey on one of my VFTs which was suffering with greenfly. It has killed off the greenfly and, although the traps seemed to die off, new traps are growing through the centre of the plant. The plant then continued tho thrive - minus the greenfly.
• Any seeds produced can be planted onto shredded sphagnum moss or pure perlite. It helps to keep the temperature relativly warm - 70 to 80 °F (21-26 °C)