Venus Fly Traps are temperate plants, not tropical as many people mistakenly assume, and so can be grown outdoors in the summer in most parts of the world including Europe. They require full sun and as much of it as possible, but in hotter regions of the world some shading and added humidity may be needed if it is particularly dry. In cooler parts of the world such as Northern Europe a greenhouse will improve growth, but is not essential. The more sun the Venus Fly Trap gets the better the colouration of the traps. If you are keeping your Fly Trap indoors then a South facing window is best. Remember that on particularly hot days, windows in full sun can be hot enough to burn your plants, even in Northern Europe . So care is needed to provide some ventilation at these times.
There are a number of suggested growing mediums into which you can pot your Venus Fly Trap. These include live Sphagnum moss, dead Sphagnum moss, peat moss, mixtures of Perlite or horticultural (silica) sand and peat moss from 30:70 to 50:50 respectively. They obviously all work, but it is difficult to say which works best without a scientifically conducted investigation. If you know of such an investigation I would be interested in a reference. Arguably the most popular medium appears to be a 30:70 mix of Perlite and peat moss, both available from local garden centres. However, you should choose a medium that is easily available to you. You should also consider peat substitutes as peat milling, the main method peat is harvested for horticultural use, is unsustainable, destroying the biological, archaeological and landscape value of peatland. There are too many alternatives to describe in detail here, but the link below should provide all the information you need.
CPS article on peat substitutes for carnivorous plants
If you are repotting a plant into a larger pot it is a straight forward process. Place some new growing medium into the bottom of the new pot and centre your plant (minus the old pot, but still surrounded by its original growing medium) in the new pot, so that the old surface is about level with the top of the new pot. You then fill in around the sides with new growing medium and soak in water from the base.
The process is a little trickier if you are potting bare rooted plants or are splitting a plant that has divided. In these cases you are starting with a rhizome and roots that have none or very little growing medium around them. In this situation the leaves of the Venus Fly Trap have a tendency to bend downwards around the rhizome, making it difficult to plant without burying the leaves. The way I pot bare rooted plants is to first ensure the pot is deep enough to accommodate the full length of the roots.
I loosely fill the pot with growing medium.
Make a hole in it deep enough to take the roots and wide enough for the rhizome.
Then the tricky part is to hold the plant gently at the rhizome in one hand and use the other hand to gather together the leaves and gently bend them back upwards to above the rhizome. Then holding them in that position release the hand holding the rhizome.
Lower the plant, root first into the hole until the rhizome is just below the surface. You can use a pencil to push the roots down if they are particularly long.
Carefully squeeze in the sides of the hole so the medium surrounds the rhizome and roots.
Extra medium can then be added and pressed down the sides of the pot to replace that which was squeezed into the hole. Then spray the surface with water to flatten the medium wash the leaves and ensure the roots are wet. The pot can then be soaked in water from the bottom to ensure all the medium becomes wet.
Tip - Medium has a tendency to gradually wash out of the bottom of the pot. To reduce this I use some perlite and plastic netting (the stuff they use to bag oranges in is ideal) cut to fit the bottom of the pot.
Place the netting in the bottom of the pot first.
I then put a centimetre or two (depending on the size of the pot) of Perlite on top of the netting and my growing medium on top of this.
The Perlite reduces the amount of peat washed out and the netting stops the Perlite coming out. Another advantage of following this tip is that the layer of Perlite improves drainage and so prevents stagnation. It also improves aeration in the bottom of the pot, which is thought to encourage healthy root growth.
Venus Fly Traps live in nutrient poor soil and have evolved an elaborate mechanism for capturing and obtaining nutrients from small animals instead. As a result their roots are not adapted to normal levels of soil nutrients and can be damaged by them, resulting in the death of the plant over a period of time. Tap water, particularly hard water contains many nutrients as dissolved salts, and other chemicals such as chlorine, that are harmful to Venus Fly Traps. So it is widely accepted that watering with tap water is not a good idea. Most growers use rain water which is free and readily available (particularly in the UK ). More expensive alternatives include distilled water or water purified with a reverse osmosis unit.
If you live near a hill or mountain you may be able to get away with stream water, so long as it is close to the source so as not to have picked up anything on its travels. I have done this when I have run out of rain water (very rare in UK ) without any ill effects. If you live in a soft water area you could risk using tap water, which has been left to stand for a few days, as a last resort. However, before doing this on a regular basis I would suggest experimenting first on a single plant over an extended period of time to see if there are any detrimental effects. One way to test how much salts are in your water would be to boil 4 litres in a metal pan until it has all disappeared, and look for a white residue in the bottom (salts). If it has no residue then it should be safe to use on your plants. However, you should still let it stand for a few days to allow volatile substances added during processing such as chlorine to disappear.
Pots should be kept in deep trays which should contain about 3 to 5 cm of water in the bottom during the growing season. During the dormancy period you can empty the tray and just keep the growing medium damp. When watering, it is recommended to add the water to the tray not onto the growing medium.
Ideal pot type
The Venus Fly Trap is a perennial plant, and in its natural environment it has a growing season during the summer and a period of dormancy during the winter. For the plant to stay healthy this dormancy needs to occur. How this is achieved will again depend on where you live. If you live in a climate similar to the Carolinas then you do not have to do anything as your Venus Fly Trap will naturally enter dormancy.
If you live in a climate that experiences cold winters then your Venus Fly Trap will also enter dormancy naturally. However, if they are kept outdoors then they will need protection from frost. If they are in the ground then they should be covered in some kind of mulch to stop then from freezing. If they are in a pot then they should be put in a greenhouse/cold frame or somewhere such as a garage with a window where it is cool (less than 10 degrees Celsius) but is frost free. If your Venus Fly Trap is kept indoors on a window sill, then it may be too warm here to initiate the dormancy state. Move it to a cool but frost free part of the house with some light, such as a garage or unheated room.
If you are in a tropical region then dormancy does not occur naturally as the photoperiod and temperature does not change significantly. In this case the plant has to be tricked into entering dormancy by reducing the amount of light the plant is getting to about 6 hours per day. This is best done gradually over a few weeks. At this point it is recommended that you put your Venus Fly Trap in a refrigerator (not the freezer section), either potted or in a plastic bag, bare rooted and wrapped in moist Sphagnum moss or something similar.
Your Venus Fly Trap should undergo a dormancy period of about 4 months, usually November to February inclusive in the northern hemisphere. During this time the growing medium should be just damp but not wet. On bringing it out of dormancy it should be introduced to sunlight gradually so as not to damage the leaves. However, some people do not worry about this as the damaged leaves are quickly replaced by new leaves that adapt to the light as they grow. If you are putting your plant outdoors, be prepared to protect them early on if frost is forecast.
When your Venus Fly Trap is mature it will naturally split, producing as many as 5 smaller plants. These can be separated and potted into individual pots, where each will grow into new adult plant in a much shorter time than a seed would.
Take a mature plant that has a number of distinct growing points.
Tip upside down and tap the pot and or squeeze the sides until the plant and soil drops out. Dont forget to use the other hand to catch the plant. If it had divided many times the root system should hold everything together.
You can wash the soil off the plant if you wish, so that you can clearly see the divisions.
The plants can then be gently prised apart. Normally the main thing to remember is not to break of the young plants until they have their own root systems, and are clearly separated from each other. There is an exception to this if you wish to force divisions from the plant. (see later)
Pot them up as you would bare rooted plants. Plants produced in this way are natural clones of the parent plant, and are genetically identical to them and each other, possessing all the characteristics of the parent.
There is a method to make divisions from a plant that has not yet divided, but this may be risky for the novice.
A mature rhizome will elongate as new leaves are produced at the front and old leaves die at the back.
Cut the rhizome into sections between where one leaf base meets the next leaf base, ideally ensuring that each section has one or more roots attached. However I have been successful with sections that didnt have any roots.
Some of your sections particularly towards the older back part of the rhizome may not have any leaves on them. This doesnt matter as provided they are kept moist and do not get infected they will eventually produce leaves, and also roots if they too are absent. Pot these sections up as you would bare rooted plants.
Tip - To reduce infection steralize your blade in a flame before use. Also plant sections into live sphagnum moss instead of peat, as it has natural antiseptic properties. Not really necessary with sections with leaves and roots but may improve the success rate of sections without leaves and roots, that take longer to establish.
Another way to get clones from your parent plant it to take leaf ‘pullings'. It is recommended that you take leaf ‘pullings' from healthy adult plants, as an unhealthy or young plant may not take the shock.
Take a healthy plant and select a leaf on the outside of the rhizome. Gently pull it downwards and out like peeling a banana.
Ensure that some white rhizome tissue is at the base. This tissue contains the undifferentiated cells that are capable of dividing to form new plants. Cells from other parts of the leaf have become specialised to carry out a particular function for the plant such as water transport, photosynthesis, protective epidermal layer etc and cannot change back.
The trap is then cut or pinched off and discarded.
The leaf is laid flat on the surface of some live sphagnum moss with the white end slightly buried. The ‘pulling' should be kept in full sun, and warmth. The moss will create a humid atmosphere around the 'pulling' and protect against microbial attack.
Leaf pullings can also be propagated in normal growing medium, and the success rate can be increased by keeping in a humid atmosphere of a terrarium or clear plastic bag. However, you must be careful not to ‘cook' your ‘pulling' by excess heat, that can often result from having plants in terrariums or plastic bags on hot days, particularly in South facing windows.
Some growers have had success at propagating Venus Fly Traps simply by snipping of the flower stalks as they grow and planting them upright in the growing medium to a depth of about a centimetre. This is worth trying even if you are a beginner, as your mature Venus Fly Traps will usually start growing a flower stalk each spring, and most growers cut these off anyway as they take a lot of resources from the plant which would otherwise be used to make traps. So you have nothing to loose, unless you really want the flowers to develop for seeds.
A more advanced method of producing large amounts of identical Venus Fly Traps relatively quickly is by tissue culture. But this technique is advanced, and beyond the scope of this guide. However, there are many articles on the web about this subject.
If you are interested in developing new varieties of Venus Fly Traps, the easiest way to achieve this is by basically letting nature take its course, and allowing flowers to develop on your plants. Pollination of the flowers is the sexual form of reproduction in plants, producing seeds that will grow into new plants with characteristics of both parents and so increasing variation. You can manipulate this process by crossing the plants that you want, in the hope that seeds are produced that will result in plants with characteristics that are highly desirable. For example you may have a red Venus Fly Trap and a Venus Fly Trap with an interesting shaped trap. You may wish to cross these two plants to try and get a plant that is red and has the interesting shaped traps. Warning, this can be a long and laborious process and you may not live long enough to see results. People sometimes collect from wild populations as they are bigger, and so the chances of something interesting arising from cross pollination are increased. Please do not collect from the wild as it is either illegal or carefully regulated.
Edited by mantrid, 25 June 2012 - 15:49 PM.