I'm going to practice getting this right too when i finally find my first Nepenthes. I plan on doing the coffee treatment in Spring and then washing it out after a few days or a week, then fertilizing normally once a month or something throughout spring into summer, where i may repeat the coffee thing again. I think it's best to dilute the coffee a bit to get good results, so i will try doing that too.
maybe I'll do this with my other plants too like my bromeliads.
That's an interesting point you brought up there Tysneps. These are my thoughts on that, having also taken Plant Physiology and considering the nature of Nepenthes as a carnivorous/insectivorous plant:
Originally Posted by tysneps
Using carnivory to supplement their diet with nitrogen and other nutrients which would otherwise be lacking or in very minute quantities in the soils that they grow in, this IAA oxidase would come in very handy in regulating growth. If the plants were to use up the nutrients stores too quickly it may lead to poor growth (lanky or stunted), or maybe even death (hypothetically) if available nutrients ran out. So the IAA oxidase may serve a very beneficial purpose in causing slow but strong growth for the overall survival of the plant by using available nutrients wisely in the wild tropics and not just in temperate regions.
In cultivation Nepenthes are usually fed and taken care of in such a way that there is almost always (depending on the grower) a constant supply of nutrients, whether from fertilizer or feeding the pitchers, and IMO adding coffee to cause the increase in growth shouldn't be a problem once growing conditions are optimal. Newman really did shed some light and important information about the effects of coffee (caffeic acid) on auxins in plants.
Just my 2 cents on the topic.