Owning Carnivorous Plants: Things to Consider

Carnivorous plants are fascinating, and can be an interesting addition to any garden. Here are some things to consider before getting one.

By Yvette Tan

Carnivorous plants, or plants that derive most of their nutrients from consuming animals or insects, have fascinated humans for millennia. Most people only encounter carnivorous plants in the movies. (Who can forget giant flytrap from outer space Audrey II from the film Little Shop of Horrors’ famous line, “Feed me”?) For others, the fascination with these exotic plants carries on to real life.

Eileen Lu, a physical therapist by profession, is one such aficionado. “I’ve been interested in carnivorous plants ever since I read about them when I was a kid. I stumbled upon venus fly traps being sold online and decided to take the plunge,” she says.

We caught up with Ms. Lu to find out how to care for carnivorous plants, as well as how to source them sustainably.

What kinds of carnivorous plants do you own?

I have an Australian Pitcher Plant (Cephalotus follicular is), Bladderworts (Utricularia sp.), Butterworts (Pinguicula sp.), North American Pitcher Plants (Sarracenia sp.), Sundews (Drosera sp.), Tropical Pitcher Plants (Nepenthes sp.) and Venus Fly Traps (Dionaea muscipula)

(Story continues after photo.)

Sarracenia “Judith Hindle”
Photo courtesy of Eileen Lu

Where did you purchase them?

Many of my plants are sourced from pitcher-plants.com or Philippine Exotics on Facebook, with others obtained from other hobbyists. At this point I would like to emphasize that people should not buy them from random sellers. Sadly, many of these plants are being poached from the wild, which endangers the native population. Be suspicious of sellers that do not know a plant’s scientific name, or sell plants with obvious damage. Seed-grown and hand-cultivated plants will look more “pristine” than their wild counterparts.

What are the challenges you face that don’t apply to regular plants?

They aren’t that difficult to care for. However, they do not tolerate regular soils or water. Since they typically grow in swamps or bogs, they are actually sensitive to minerals and chemicals that regular plants need.

I grow them in a medium consisting of 50/50 cocopeat and pumice. The cocopeat needs to be well soaked and washed to get rid of excess salts that accumulate during manufacturing.
Watering is usually done by the tray method, to simulate a bog-like environment. The plants sit in a tray of water that is refilled once empty.

Because of their sensitivity to minerals, they should not be grown in clay pots.

What kind of water do they require?

The recommendation is water that is low it total dissolved solids (TDS.) Generally a TDS of 50ppm or lower is considered ideal. Distilled water has a TDS of zero, so it can be said to be the “best” water for them, however the cost can be prohibitive.

Some hobbyists use reverse osmosis water, which is cheaper, specially if you have your own system at home. I personally use rainwater (TDS of around 3 to 15ppm, depending on weather and pollution conditions) or aircon runoff (approximately 10 to 16ppm TDS, depending on your aircon). Nepenthes are the exception, as they can tolerate our local tap water just fine (~80ppm)
Someone who is seriously considering getting into this hobby should invest in a TDS meter to assess the suitability of their water supply.

(Story continues after photo.)

Stapelia gigantea
Starfish cactus
Photo courtesy of Eileen Lu

Do you have to feed them or can they find their own food even if they’re growing in the city?

They are more that capable of catching their own food. Flies, mosquitoes, cockroaches, ants, etc. provide ample food for carnivorous plants. However, feeding them is a good way to speed up growth and observe their interesting feeding mechanisms.

Fish food, particularly those marketed toward fighting fish, are good for carnivorous plants. However, one should not overfeed them as well as this may cause mold to grow on undigested food. A rule of thumb is to feed only one or two leaves per plant once every two weeks.

What’s the best carnivorous plant for a beginner?

Most people will want the venus fly trap, since it’s the most famous and has the most interesting feeding behavior. However, venus fly traps can be hard to grow because they are native to temperate climates and may require dormancy.

The plant I would first suggest is a tropical pitcher plant (Nepenthes sp.), particularly the fast-growing hybrid varieties. Most of them are native to tropical Southeast Asia, with many naturally found in the Philippines already. This means they are already suited to local conditions. They also tolerate tap water, and are watered like regular plants, rather than the tray method.

This means a beginner will not need to make many adjustments, apart from providing an appropriate growth medium and plastic pot. Nepenthes also have the advantage of requiring partial sun only.

The second plant I would suggest is a sundew (Drosera sp.) Although these plants already require special water and the tray method, they are hardy and forgiving of beginner mistakes. Most varieties also set seed and germinate easily.

(Story continues after photo.)

Drosera spatulata
Spoon-leaf sundew
Photo courtesy of Eileen Lu

Are there any plants that you don’t have yet that you want to own someday?

At this point I already have most of the plants I want. Since I live in a townhouse, some types are not suitable due to their space requirements.

What’s the best thing about caring for carnivorous plants?
I would say the fact that they eat insects, and they exhibit traits not found in other plants.