Expert: Christopher Littrell - 9/8/2010

Question
I have several of these wonderful plants they are growing well no problems however they are not producing new pitchers I have them in bright but filtered light, they are receiving lots of air flow, i water them daily I have been told to fertilize them monthly with a 20-10-20 at a very weak solution and then i have been told not to feed them, I have them potted in shredded cedar chips with some orchid bark mixed in and some spaghnum with no fertilizer they are in hanging baskets, the plants will produce some pitchers but them they turn brown or abort, the plants are in great shape just no new pitchers being produced
thanks for your help  linda

Answer
Hello Linda,

Since this is a systematic problem with all of the plants, it looks like you need either more light, or less air flow. You can try and start with more light since Nepenthes need high intensity light, just short of full sunlight really. They are partial light plants in the wild, getting a few hours of sun through the branches of trees and then direct morning and evening light when the sun is not so intense. Try increasing the amount of light a little more and increase the number of hours a day they receive that light. If the plants are inside, it would be easy to merely add more shop lights and move them to a brighter window and remove any screning that inhibits light. If they are outside, you will need to adjust the occluding screening or mesh to try to allow more direct light in during the morning and evening hours and provide cover only in the noon hours when it is too hot and bright.

Air flow can be a problem if it is leeching humidity from the plants, causing pitcher failure. If the plants are having air blown directly on them constantly, this could be a problem. Indirect air flow might be better. A fan pointed at a wall, or if outside, just whatever breeze there is.

When Nepenthes have pichers, they do not need fertilizer. I have never fertilized mine at all, except the natural method of letting them catch insects and providing them with a few insects manually as needed to ensure they get enough nitrogen. When they have no pitchers for a long time, then they might need to be kick started with some weak 1/4 or even 1/8 strength foliar feed orchid fertilizer wiped or sprayed on their leaves once every two to four weeks. If fertilizing does not do the trick, then there is something else in the climate that they are getting too much of, or not enough of. Be mindful that strong fertilizers can harm Nepenthes and burn their leaves, damaging the tendrils and new pitchers. You might stop fertilizing for a while and see if that helps too.

To give you an idea of how mine are situated. I have mine set up indoors about 8 inches from 6 florescent 40 watt cool white tubes of the four foot variety for 16 hours a day. They are kept in 80 degree temperatures in the day and down to about 70-75 degrees at night with ambient humidity of around 50% I have a couple of the tougher varieties, a N. truncata and several N. sanguineas plus cuttings. All of the plants, including the cuttings and the usually sparsely pitchering N. truncata, are producing ever larger pitchers by the bucketload.

Christopher