Question
I live in Northern Colorado, and have been growing a small N. rajah since early April. It grows in a large pot of a peat/ sphagnum/vermiculite soil, around 5 inches from a bright fluorescent light. I have also used only distilled and rainwater for it, and kept the soil very moist to wet. Recently, it produced a leaf with the mature peltate tendril characteristic, but the next 2 have reverted back to immature leaves, and the newest leaf bud appears to have a brownish tinge to it that I have never seen. the tip is also brownish, though the color is lightening up. Is this something to expect as it grows up or is something wrong?

Answer
Welcome to the frustrating world of growing Nepenthes rajah!  This plant grows in the high elevations of Borneo where the temperature and weather are fairly consistent.  It dislikes extreme changes in its growing conditions, including temperature, lighting and humidity.  If any of these factors fluctuate wildly, the plant will often produce smaller leaves.

My guess is that your plant liked the growing conditions when it produced the larger leaves, but when something in the growing environment changed, it started growing smaller leaves.  Plants will sometimes do this to prevent excess moisture loss through their leaves.

It's possible that the lighting is too bright, the daytime and/or nighttime temperature is too high, and/or the humidity is too low.

So move the light a bit further away from the plant.  By doing this, you will decrease lighting and temperature, which in turn will increase relative humidity.  You will need to wait at least 3 months before you see any noticeable difference in your plant.  This species grows very slowly, so you'll need to be very patient.

Good growing!
Jacob Farin