Cultivating Carnivorous Plants (2015)
DIONAEA
A Venus Flytrap, Dionaea muscipula, in the wild.
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For my 13th birthday, there was
only one thing I wanted, a Venus
Flytrap, Dionaea muscipula. Our local
hardware store received a shipment of
Venus Flytraps in small, round pots
covered by clear, plastic cups a few
weeks before. I had no idea how to grow
it, but I knew that any plant that could
catch a fly in a trap that closed in a few
seconds was fantastic!
Lo-and-behold, I got one! My first
carnivorous plant! I carefully followed
the terrible directions that came with my
botanical wonder, but I later became
concerned that the plant was dying.
Over the course of a few weeks, the
handful of traps dwindled to two. Then,
as I grew more concerned, I took a
A small group of plants in the wild, probably growing from a
weekend vacation to visit some family
single rhizome which divided as the plant matured. The red
friends. They took me to a bookstore, coloration on the outside of the trap is not unsual, and within the
where I found a book on carnivorous
range of typical variation for wild plants.
plants, and I became hooked on this hobby!
Charles Darwin called the
Venus Flytrap “the most wonderful
plant in the world,” and, it has been
for generations of carnivorous plant
growers. The small, rosetted plant
grows from a white rhizome (often
mistakenly called a “bulb”), which
only produces a few, thin, black
roots and five to seven traps. The
one-and-a-half-inch
(four
centimeter) traps are at the end of
four-and-a-half inch (12 centimeter)
long petioles.
Despite
popular
culture’s
opinion that Venus Flytraps are
native to some tropical rainforest,
they are historically native to a 60
mile (97 kilometer) radius of
Venus Flytrap in the wild with typical coloration.
Wilmington, North Carolina. In
1978, a population of 86 plants was
found in Florida’s Apalachicola National Forest. Further study revealed multiple locations of plants, too many
to have been introduced by human intervention. These populations most likely originated from seed carried
on the muddied feet of birds that stopped to rest and refuel in Wilmington’s and the Apalachicola National
Forest’s wetlands. Additional populations, planted by humans some years ago and now naturalized, can be
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CULTIVATING CARNIVOROUS PLANTS
found in the New Jersey Pine Barrens and Washington state.
The theory that enough Venus Flytrap seed could survive the journey from Wilmington to Apalachicola
National Forest to seed small populations is not farfetched. The seeds are small, black, and easily germinate.
Fresh seed has a nearly 100% germination rate, and the species does not require a cold stratification period to
germinate. Upon reaching maturity, the white flowers can self-pollinate, but they require the assistance of a
bee or paintbrush. Successfully pollinated flowers will produce up to 30 seeds.
A Venus Flyrap in cultivation proudly displaying two recent captures. Opiliones (“Daddy Long Legs”) are a
favorite treat for Venus Flytraps outdoors in more northern climates.
In Cultivation
Happily, Venus Flytraps are among the easiest carnivorous plants to grow, if cared for properly. The first
thing to know is that plants are well-adapted to growing under the blazing sun of the long, summer days in
North Carolina. Therefore, they require as much light as possible, but, if grown under artificial light, a dark
night time is necessary. In addition to strong light, the plants grow in areas that have constantly moist but not
wet soil thanks to near-daily afternoon showers from spring to fall. As a consequence, they will need moist,
but not wet media during the growing season and drier media during the winter dormant period. If possible,
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be sure to give dormant Venus Flytraps
some light, in order to prevent rot. If it is
not possible to expose them to light, dust
their rhizomes with a non-copper based
fungicide a couple weeks after dormancy is
induced.
The Types
There is only one species of Venus
Flytrap, Dionaea muscipula. As a consequence,
the only “types” of Venus Flytrap are
cultivars, individuals with certain, unique
traits that are desirable. Currently, there are
several hundred named cultivars. Not all
have been officially published or recognized,
but most consist of color variations on
certain portions of the plant and/or natural
A red cultivar.
variations in certain characteristics. Because
Venus Flytraps only possess a limited number of characteristics and natural variations, it is actually possible to
calculate the number of expected possible natural combinations, and, thus, the number of expected natural
cultivars. (This calculation does not account for any drastic mutations, such as those with “Fused Tooth”).
In order to determine the number of expected natural cultivars, I charted all of the characteristics of
every cultivar I could find and came up with the following table of natural characteristics being expressed in
cultivars:
Item
Possible Options
Options Numerically
Parts of Plant
Petiole, Inner Trap, Outer Trap, Cilia
4
Color of Plant
Red or Green
2
Petiole Length
Short, Regular, Long
3
Cilia Length
Short, Regular, Long
3
Cilia Shape
Triangular or Regular
2
Size of Trap
Small, Regular, Large
3
By multiplying together the numerically translated options, I could
come up with the total number of expected natural variations: 432. By
checking random descriptions generated by the above table against the
cultivar descriptions, it was possible to account for most cultivars. For
example, a plant with short, green petioles, large traps, red on the inside
and green on the outside, with green, regular sized and shaped cilia
matches the description for ‘Big Mouth’. A plant with regular, red
petioles, regular traps, red on both the inside and outside, and regular
sized, red cilia matches the description for ‘Akui Ryu’. (Of course, plants
with drastic mutations, such as those that cause the plant to become
variegated, fuse cilia (“teeth”), or mutate the trap shape, are not counted
‘Cupped Traps’ Cultivar.
among these permutations).
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One of the interesting things that I discovered in
conducting this exercise was that some combinations, such
as a plant with short red petioles, small traps, red on both
the inside and outside, and triangular, green cilia matched
multiple cultivars - ‘Bohemian Garnet’, ‘FTS Crimson
Sawtooth’, and ‘Red Piranha’. The only real difference
between these cultivars, at least in growers’ experiences,
appears to be the genetic lineage of the parent plants. (The
difficulty in separating out cultivars is demonstrated in the
photo to the right, which is of a ‘Pink Venus’. The plant in
the photograph, however, could match any one of a handful
of other cultivars, something which becomes fairly obvious
as one collects cultivars). Because of how easily confused
It would be hard to distinguish this as the
cultivars are, growers should be careful in choosing Venus
Flytrap cultivars, as many cultivars will appear almost
cultivar ‘Pink Venus’ without a tag.
identical in identical conditions.
My standard growing guide for Venus Flytraps follows:
✵
Media: A mix of one part sphagnum peat to one part perlite works very well. Sand can be substituted
for perlite, but perlite appears to increase growth, somewhat.
✵
Moisture: Keep moist. The best way to do this is to water via the tray method, i.e. keep a shallow tray
full of water under the plant’s pot, during the growing season. In winter, this tray should be allowed
to evaporate and the media dry slightly before watering.
✵
Pot Size: Deep plastic pots are best as the plants have deep roots. Personally, I find that window
boxes placed in shallow seed-starting trays filled with water work very well. The 2.5 inch pots that
plants can be found in at retail stores around the world are far too shallow for full grown plants.
✵
Feeding: Venus Flytraps need to be fed a lot. If it is not possible to keep the plants outside, where
they will prolifically pick off insects, an experiment at the University of New Hampshire proved that
watering with a Poinsettia Fertilizer will keep the plant producing more, larger traps than unfertilized
plants.
Please also note that traps should not be stimulated to shut unless prey is contained within the trap.
The rapid cell growth that causes the traps to close will also harm the long-term growth of the plant.
✵
Temperature: Venus Flytraps are used to the long, hot summers of North Carolina and prefer 85°+
F (30° C) temperatures. Cooler temperatures will slow growth. Freezing will induce dormancy.
✵
Dormancy: Dormancy is important for the long-term health of a Venus Flytrap. Daytime
temperatures which do not exceed 50° F (10° C) will induce partial dormancy. Although older texts
will state that Venus Flytraps should not be exposed to freezing temperatures for long periods of
time, growers in New England have been successful in allowing them to overwinter in unprotected
bog gardens, but survival rates are higher if the bog garden is covered with several inches of mulch.
If it is not feasible to grow Venus Flytraps in an outdoor bog garden, they can be overwintered in
plastic bags with a bit of damp paper towel in the refrigerator.
✵
Propagation: Venus Flytraps can be propagated by seed, leaf-pullings, or division.
o
Seed: The slowest way to propagate Venus Flytraps is via seed. Although high germination
rates are expected for seed sewn on a suitable media and kept moist, it will take several years
to obtain a mature plant.
o
Leaf-pullings: Leaf-pullings are the easiest and most common method of propagation. The
leaf should be pulled from the rhizome, with as much of the rhizome attached as possible.
Then, place on top of suitable media, cover the rhizome end with a little bit of media, and
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place in a shaded area that stays around 75° F (24° C). It may be beneficial to cover the pot
slightly with plastic wrap to increase ambient humidity, but watch for signs of rot.
o
Division: Venus Flytraps will naturally divide and form new plants. When a new growth
point is spotted, the plant may be divided. Division is best done during dormancy, shortly
before spring growth begins. Divide the rhizome in as many pieces as there are growth
points, while trying to keep as much of the root system intact as possible.
.
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