Question
QUESTION: Hello SNW,
I am asking your opinion on what kind of plants I should get for my particular type of terrarium.  Yes, I know you guys are not very big fans of these things, but I think I have the time and maintenance required to grow specific plants in these tanks.  Now, on to the details.  It is an exoterra terrarium and is the greenhouse type.  Here's the website of it http://exo-terra.com/en/products/glass_terrarium.php.  It is a greehouse terrarium with two 26 watt flourescent bulbs, but temperature inside is always seasonally fluctuating.  I live in San Jose, California.  The tank is on a south facing window that is shaded.   I believe that Heliamphora will suffer during summer where temperatures are in the 80s and Lowland Nepenthes will suffer in winter when temperatures are in the 50s.  I already have the tank and lights so I might as well use them.  So, my question is what kinds of plants would you think would thrive with the controlled environment of a terrarium?

ANSWER: Oh, Oh!  You triggered my soapbox speech.  

Yes, I'm not at all a fan of terrariums because it takes away from the most important concept about carnivorous plants, which is carnivorous plants are plants, plain and simple.  As plants, they require sunlight and water for energy.  They also have the same adaptive mechanisms to adapt to lower humidity just as regular plants do.  The only difference between carnivorous plants and regular plants is how they get their fertilizer.  

Sure there are carnivorous plants that have a very narrow range of growing conditions and should be grown in a controlled environment.  But that's because of the individual nature of those plants and not because they're carnivorous.  There are also non-carnivorous tropical plants that also have very narrow growing conditions and may require a controlled environment as well.  So before I can even offer advice about what plants to grow, I need to make sure that you have the fundamental concept of what a carnivorous plant is - a plant.  If I didn't do that, I'd be doing you and other growers who may read this a disservice.

The most common problems with terrariums, besides sidetracking the issue that plants have adaptive features to adapt to lower humidity, are low light and constant high humidity.  It's too much to get into in this format, but suffice to say that if the lighting is too low and the humidity is constantly high, you end up with a weak lazy plant that can't withstand sudden changes in its environment.  

If you really think it's necessary to keep a terrarium, then first try growing those plants that have narrow growing conditions.  These include Heliamphora, Nepenthes ampullaria, Nepenthes bicalcarata, and any of the wooly sundews, such as Drosera lanata and Drosera paradoxa.  These species, however, are difficult to find, and that's mostly because they're difficult to grow in cultivation because of their narrow growing range.

Some plants that are easier to find and have a wider growing range are Drosera adelae, Drosera spatulata, Drosera capensis and Drosera prolifera.  In general, I don't recommend Nepenthes for terrariums unless it is those mentioned above.  The reason for that is because Nepenthes are large plants and can quickly outgrow a terrarium.  If you want to try a Nepenthes, I'd recommend Nepenthes gymnaphora, Nepenthes talangensis, and Nepenthes lowii.  With these species, they either have small pitchers or grow incredibly slowly as to not out grow the terrarium any time soon.  Cephalotus is also a possibility.

So those are my recommendations, but my ultimate recommendation is to avoid the terrarium altogether.  The vast majority of carnivorous plants will adapt to your climate as long as you provide the proper lighting and water.

For more information about growing carnivorous plants, visit the following links:
http://www.cobraplant.com/ebook
http://www.cobraplant.com/podcasts
http://www.cobraplant.com/caresheets

Good growing!
Jacob Farin

---------- FOLLOW-UP ----------

QUESTION: Yes, I've had to understand that thorugh the many experiences that I have.  Don't worry, I already know the basic care for these things are and want to challenge myself.  Since I live in Zone 8 (San JOse, CA) I guess lowland types are the way to go.  How can I take care of them dyuring winter thwere low temperatures can stunt their growth?

ANSWER: Actually you should focus on the highland plants because they can tolerate cooler temperatures:
N. sanguinea
N. truncata
N. ventricosa
N. x 'miranda'
N. mikei
N. x 'Deroose Alata'

As long as the lighting is very bright, they grow well as houseplants.  The other plants I mentioned earlier are also highland plants.

Good growing!
Jacob Farin



---------- FOLLOW-UP ----------

QUESTION: Oh yes, I also have an ultrasonic humidifier in the terrarium.  Which plants would enjoy the misting?

And, would Nepenthes Eymae fit in a terrarium?

Answer
The ultra highland plants, such as N. rajah, N. villosa, N. inermis. N. dubia, and N. hamata.  N. eymae will fit in a terrarium initially, but within a few years it'll outgrow it.  This species also grows well as a houseplant, so a terrarium isn't at all necessary for it.