Dionaea muscipula 'B52'.
Dionaea muscipula is found naturally in the coastal plain of southeastern North Carolina and northeastern South Carolina. The plant is surprisingly adaptable considering its narrow distribution in the wild.
The main requirements for growing Dionaea muscipula are:
(1) The plant needs lots of light. Give it full sun if you can. Grow it outside as much as you can. It also makes an excellent indoor plant but requires more light than it can get on a typical house window sill.
(2) The pot with the plant must always be sitting in pure water. If your tap water has a total dissolved solids (TDS) less than 90 ppm (check with your city, water company, well test, or measure with a TDS meter) you can use it for your carnivorous plants. If the TDS is higher than 90, use distilled, reverse osmosis, or clean rain water. Filtering water will NOT remove the dissolved salts.
(3) If the plant is not catching its own food, it needs to be fed in the traps with live insects, rehydrated dried blood worms, or other kinds of fish food high in insect-derived protein that can be conveniently rehydrated. If you use dead food, the traps need to be massaged to stimulate full closure and digestion.
If you grow your plants indoors or just bought a plant please see the Check List for Growing Dionaea muscipula. If your plant needs repotting please see Dionaea Leaf Pullings Step-by-Step. A well kept VFT will need to be repotted every year or so.
Dionaea muscipula isn't very picky about soil. It grows well in pure Sphagnum moss (live or from dried), pure Sphagnum peat, and the standard 1:1 peat:sand "CP mix". Avoid perlite, pumice, and other potentially salty soil components. What does matter is how tall the pots are and consequently how far the crown of the plant is from the water level. The plants do not enjoy being soggy but must always be wet. The wetter the soil the taller the pot. In shorter pots the soil should be more sandy. Avoid pure Sphagnum moss or pure peat in short pots. In any case the water level should always be more than 5 cm (2 inches) below the surface of the soil.
Sow seeds of Dionaea muscipula on the surface of your medium of choice. About 3 mm of washed quartz sand over CP mix works well as does a layer of finely chopped live sphagnum moss over CP mix. The live sphagnum can overgrow the plants so keep a close eye on the seedlings if you use it. Finely chopped long fibered sphagnum over CP mix or CP mix alone also work well germinating seeds. The main problem is the nutrients in peat encourage the growth of cyanobacteria (AKA bluegreen algae) that can overgrow the small, very slow growing seedlings. Washing the peat helps cut down on cyanobacteria and moss. However the nutrients in the peat, what small amount there is, give the small seedlings a boost. The soil should be saturated with pure water.
What you do after sowing the seeds depends on what works best for you. Everyone has their own preferred routine. I lightly spray the seeds with water and put the pots in plastic zip-lock bags under but not too close to florescent lights. A temperature between 20°C to 25°C (70°F to 80°F) works best. After the seedlings get a few true leaves (the ones with traps), I remove the pots from the plastic bags and move them to bright terrarium or greenhouse. Please see Sowing Seeds Step-by-Step for more details on starting seeds.
The seedlings are very slow growing. It could easily take 5 years to get a mature plant from seed if they are not fed regularly. Experts with greenhouses can get mature or close to mature plants in three years. You can get a mature plant in two years if you feed it in the traps as much as the plant can handle. But no one grows Dionaea from seed commercially except to find new varieties. The usual technique for commercial propagation is sterile culture called tissue culture or micropropagation. They propagate only the very best selected plants which may be one in a thousand from seed. Expert growers may also fertilize their plants. This is tricky to do safely. DO NOT fertilize your plants unless you don't care if you kill them. Feed them in the traps with Dried Blood Worms.
New Dionaea seedlings will tend to grow for about 4 months then stop growing. They are expecting winter to start a that point. They can be tricked by keeping them warm under intense light and feeding heavily. As soon as a new trap opens, feed it with a small piece of hydrated dried blood worm. When it reopens remove the remains of the previous meal. That will probably result in it closing the trap. When the trap reopens again in the next day or so, feed it again.
If you live in USDA zone 8 or warmer, as much as possible, try to grow your larger seedlings and mature plants outside. They will grow best in full sun if you live in an area that is humid or cool in the summer. If where you live is hot and dry, full morning sun and then part shade is appreciated. The use of 10% or 20% shade cloth with full sun works well (if you can find it—most shade cloth is 50% or more and that is too shady).
In USDA zone 7 it is problematic growing Dionaea outside without a heated greenhouse but it can be done. During the winter, if the temperatures don't stay below freezing for more than a week at a time you can keep the plants outside fully exposed to the rain and snow unless there is an early or late freeze. The plants will survive being frozen solid for a week or longer if they are fully dormant and protected from drying out. If they are not fully dormant, freezing weather can kill them. When the plants are being overly protected or have started to grow and then get frozen they are easily killed. Do not let them dry out as the biggest danger is freeze-drying. Use of pine needle mulch or row cover cloth helps prevent freeze-drying.
In very cold climates (USDA zone 6 and colder) the plants will require substantial protection if grown outside. It may be best to put the plants in a heated greenhouse, a south facing window of a garage, or cover them with a foot of straw or pine needles during the winter. Although it is probably a good idea to supplement the light if you have the plants in a garage window during the winter I do not recommend bringing them into the house or basement and putting them under lights for the winter. It will get them out of sync with the seasons. It is better to just keep them indoors under lights all the time than to switch back and forth.
Dionaea appreciates seasonal light cues. Winters along the Carolina coast are relatively mild and dry so you do not need to refrigerate the plant or otherwise force it into dormancy with cold. It just needs enough natural light to know what season it is. You know the plants are getting enough light cues when they send up flowers in the spring. You can accomplish this by having them in a room that gets good sunlight around sunrise and not having your plant lights come on until 7 or 8 AM. I use 25W of fluorescent lighting per square foot of growing area and keep my lights on 16 hours a day. I also use 4000K bulbs because my plants have always done better or at least looked better to me than ones grown under 6500K bulbs. My plants grown this way are 8 years old from sterile culture and grow continuously. They have been repotted each time the growth point hits the edge of the pot, which is about every 18 months.
Another option I have considered but not tried is using a light timer that adjusts the on time according to the date. Since the timers are designed to turn lights on at night, set the timer six months and 12 hours out of phase with the current date and time. This will result in the lights being on during the day and in phase with the current season. You probably will need 50W of fluorescent lighting per square foot of growing area for the plants to get enough light. With the amount of heat generated by the lights I would put the plants in rather large pots and use up-side-down jugs of water in a tray to keep them from drying out.
— John Brittnacher
For more information please see:
Degreef, John D. (1988) The Electrochemical Mechanism of Trap Closure in Dionaea muscipula. Carniv. Pl. Newslett. 17(3):80-83,91-94 ( PDF )
Degreef, John D. (1988) The Evolution of Aldrovanda and Dionaea Traps. Carniv. Pl. Newslett. 17(4):119-125 ( PDF )
Szesze, Michael (1995) A Venus Flytrap Flipbook. Carniv. Pl. Newslett. 24(1):20-21 ( PDF )
Dionaea muscipula sprout. Note the non-carnivorous cotyledons with the seed still attached. The first true leaves have traps.
This is the same seedling a few weeks later.
The seeds were planted a little close together.
Dionaea muscipula has seasonal leaf forms. In the spring and fall, the leaves have short wide petioles and hug the ground like the plants in the picture above.
During the spring as the flower stalks emerge, the plants tend to put out upright leaves with long narrow petioles. Some cultivars do not produce upright leaves like these.
This is how healthy Dionaea plants look at least 3 month of the year while they are dormant outside. Some growers repot their plants every spring just as they start growing. These were repotted a week after this picture was taken.