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

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

Color of Plant

Red or Green

Petiole Length

Short, Regular, Long

Cilia Length

Short, Regular, Long

Cilia Shape

Triangular or Regular

Size of Trap

Small, Regular, Large

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).

CULTIVATING CARNIVOROUS PLANTS

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.

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.

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.

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.