Question
A couple of years ago, I purchased a N. Truncata (highland variety). The pitchers had come off during shipping, and since then, it's never produced new ones. But it's stayed green, and every now and then produces a few more leaves.
I noticed the first and largest leaves were starting to turn black and and fall off, and I was okay with that, as it was also producing new leaves as well. The leaves would have to die off eventually, right? Anyway, I went out there today, and the plant bent over, and the stem itself is turning slimy and black and is pretty thoroughly rotten.
I have it in a lovely little terrarium where the humidity stays high and the sunlight isn't too severe, as they were grown in 80% shade. This hasn't been changed in about a year.

Is there any way I can save it? Should I sever the rotten portion of the stem and put the little bit that's still good with the new leaves in some root-growing stuff, or should I cut it all off and start from the roots up?
If you could also tell me what I did wrong to make it not produce pitchers, that'd be nice too.

This plant means alot to me, and was a pretty hefty investment. Please help me. Thank you.

Answer
Hi Liz,

Unfortunatly, with these sort of symptoms, the plant is on its way out.  This type of infection (possibly bacteria) is extremely difficult to treat once it starts.  Usually by the time you catch it it's already too late.  There is a product that will take care of bacterial infection on plants, but it's most suited for earliest signs of infection.  At this stage, with the stem turning completely black and slimy, the amount of the product you'll need to use to kill the bacteria will also kill the plant.  It won't be very useful cutting the stem.  It might work with other plants, like sundews, but not with Nepenthes.  Even in my hands, the plant might not make it at all.  It's one of those situation in which the normal course of action to treat this plant might actually kill it.

Fortunately, these plants are relatively inexpensive, and you can start over with a healthy plant.  When you do so, ditch the terrarium.  The terrarium and low light are the two main culprits in your case.  The majority of Nepenthes commonly found in cultivation don't need constant high humidity.  These plants adapt perfectly well to lower humidity.  Over the years, I've had numerous Nepenthes truncata in my home as houseplants.  They all grew just fine and produced very large pitchers.  Right now they're residing in my greenhouse because they got too large for my home.

Constant high humidity does more harm than good for plants.  It is a serious promoter of bacterial and fungal infections.  Plants in constant high humidity also develop soft leaves that are prone to infections.  

When growing plants in terrariums, it's also difficult to get the lighting intense enough for many sun loving plants, like Nepenthes truncata.  If the light levels are too low, plants will fail to produce pitchers.  Over time they weaken from lack of energy and don't have the strength to support their own natural immunity.

Overall, growing plants in terrariums makes it a lot harder on yourself, particularly when it comes to Nepenthes truncata.  This and many Nepenthes species acclimate extremely well as regular houseplants.  When they grow in lower humidity and very bright sunlight, they actually develop natural defenses to protect themselves from fungus and bacterial infection.  

For more information about growing Nepenethes, read our care sheet online:
http://www.cobraplant.com/caresheets

Good growing!
Jacob Farin