Question

Nepenthes ventrata  

Nepenthes ventrata   Hi, I've been growing this Nepenthes ventrata for about a year now and it hasn't produced very many pitchers since I got it, but the stems are getting very long. The pitchers it has produced are much smaller than the original ones. The leaves have also gotten progressively shorter and thinner. Any tendrils with undeveloped pitchers turn black and die. I have it in a south facing window with four T-5 fluorescent lights on above it for 14 hours because there are many tall trees in my backyard. I give it distilled water whenever it starts getting dry and it is potted in long-fibered sphagnum moss and perlite. I live in southwest Washington State.

Do know why it's leaves are getting so short and thin? Does it need more light? Not enough nutrients?

Thanks!

Answer
Your plant is showing classic signs of low light.  The leaves are pale and thin, and the stem is very lanky.  Granted that the plant is in its vining stage, but the spacing between the leaves are typically shorter than that when the lighting is bright enough.  Insufficient lighting is also the most common cause of poor pitcher development.  I know you have it under T5 lights, but it's not adequate for this particular variety.   

I've found that this variety prefers the spectrum found in natural sunlight.  Some varieties of Nepenthes, such as Miranda, grow fine under fluorescents.  Others simply don't.  Ventrata is one that doesn't.  Typically we see them produce pitchers in summer and early fall.  During winter, they simply stop producing pitchers because the light levels are not strong enough.

For now, it's simply a waiting game until we get into warmer weather when you can place your plant outdoors where it gets a few hours of direct sunlight.  Every summer I place one of my large ventratas under a tree where it gets dappled sun during the day, and a blast of sun during the late afternoon.  It produces very nice pitchers for me every time.

I also recommend fertilizing your plant.  Give it a weak solution of orchid fertilizer, 1 teaspoon per gallon, every two weeks.  This will give your plant a nutritional boost so it can grow larger leaves.  

For more information about growing Nepenthes, I strongly recommend watching Volume 3 of the Grow Carnivorous Plants DVD series.  Since you are in Washington, I also recommend visiting us during our open house.  You can see how we grow these plants during the summer months.
http://www.cobraplant.com/

Good growing!
Jacob Farin