Expert: Sarracenia Northwest - 1/13/2012

Question
Hi, I have a few Nepenthes that have some pitcher lids that are drooping. There doesn't seem to be any other problems with the plants. The plant in the picture is a Nepenthes khasiana, but my N. truncata 'Pasian' lids are also drooping so that the pitchers are almost completely closed. I grow my nepenthes in an indoor terrarium. I've been growing these plants about one year. It has 54-watt fluorescent lights on the top and those usually keep the temperature around  68-74 degrees. There is a fan to cool the lights. I raised the lid of the terrarium about 1 inch so that it will get some air circulation. I water them with distilled water and I also spray the plants in the morning and at night. They are potted in long-fibered sphagnum, orchid bark, and perlite. I live in Vancouver, WA.

In the morning the lids seem to perk up a bit, but by the middle of the day are drooping again. Not all of my nepenthes are doing this. Do you know why the lids seem to be drooping? Is it humidity or temperature? Thanks!

Answer
Hi Reggie,

It looks like you have a couple things going on here.  With your N. khasiana I see a couple of good looking new leaves growing, and that the leaves with the pitchers have some brown edges.  Those leaves may be on their way out, and pitchers will often do this when they are getting ready to depart.  

The other factor may be spikes and crashes in your humidity.  Is your lid open the inch all the time or do you open and close it some?  What about the fan?  Is it on all the time, or do you shut it off at times?  Inconsistency is a Nepenthes pitcher killer.  Your misting may be adding to this problem too.  Here's a recent response I gave regarding this issue:  http://en.allexperts.com/q/Carnivorous-Plants-711/2012/1/misting-nepenthes.htm  Misting a Nepenthes as a houseplant doesn't really help them, and in a terrarium it's almost downright silly since it's plenty humid in a terrarium anyway.

Here's my recommendation.  Go ahead and open the terrarium some, but just leave it that way if you've been opening and closing.  Same with the fan.  Either have it on, or off, but not on and off.  Also, stop misting.  If for some reason you need to clean leaves, that's fine, but no daily misting.  What the goal here is consistent conditions that don't change much other than the normal light/dark cycle.  This will allow your plants to grow their pitchers and not be reacting to changing conditions.

On a side note, neither of these plants need to be in a terrarium.  I had a great looking N. khasiana growing in an East Facing sliding glass door several years ago.  Any of the N. truncatas do fine as regular houseplants.  They grow a bit slower, but they will definitely adapt to lower humidity.  They just need a sunny window.

Good Growing!

Jeff Dallas
Sarracenia Northwest
http://www.cobraplant.com

Follow-up:

Hi Reggie,

If your windows don't have good sun, stay with your lights.  In full shade Nepenthes will not pitcher.  The window the plant in the picture sits gets around 4-5 hours of direct sun in the summer.

Jeff