In June of 2011 I bought my first Cephalotus follicularis; the so-called "vigorous" clone from D. Hastings. I knew little about the care and cultivation of this mysterious species, but as is my way, I sought every snippet of information available to help me forge a plan for its care. This is the plant shortly after I received it, in a 2" pot:
And here is the same plant, one year later, measuring over 5" across:
I started out caring for the plant by housing it in an indoor terrarium, equipped with fluorescent lights, as many people do when they first acquire this species. It did OK for a while, but in the terrarium environment it was inclined to mildew on the new pitchers, and it just looked “stressed” to me, so I soon moved it to the greenhouse, where ambient humidity was modest at best, but light levels were higher and night temps dropped into the fifties consistently. In September 2011, I built a new greenhouse dedicated to Highland/Intermediate climate Nepenthes, and the Cephalotus was moved into that grow space for the Winter also. When light levels dropped and temps got cooler, the Cephalotus (I had 8 plants of various clones by then) went into semi-dormancy, as I was told they will do when exposed to seasonal changes. Pitcher formation gradually slowed, then ceased by January, and there was little activity until March, when many new non-carnivorous leaves began to form. Soon after that, several plants started making bloom spikes, and three of these plants are now in bloom or about to flower. (Including my “Hummers Giant”!) I suspect Cephalotus benefit from the chance to experience some degree of “dormancy” for long-term health, although many experienced growers related to me that they have grown plants for many years in terrariums with little or no variation between Summer and Winter conditions, with no ill effects observed. (However, plants grown this way are unlikely to flower, I am told, since the flowering response is triggered by seasonal climate changes)
As for soil and water, I have potted my plants in a mix that is essentially 50% washed Peat, 50% coarse quartz sand, but with a handful each of horticultural charcoal and fine grade Fir bark chips. The top of the pot is dressed with 1/4″ of the same coarse quartz sand, as some growers report that this tends to reduce the chances of crown rot or other fungal/bacterial disease. Water used is always collected rain water or filtered municipal water from the city (our city water has a TDS reading of less than 50PPM, which is exceptionally mineral-free). I have occasionally applied a very dilute Orchid fertilizer (no urea) to the soil, rinsing thoroughly with clean water a day or two later, with no ill effects. I can’t say that fertilizer has a profound effect on their growth, since I didn’t use a control plant for comparison. However, there have been studies done that show that Cephalotus do get a portion of their nutrients through the root system.
In all, I would say that my experience with this species has been very rewarding and it is not at all difficult to grow well as long as you observe its core requirements: bright light (natural sunlight preferred), simple, well-drained soil mix, clean water, and don't allow the soil mass to heat up! (plant it in a very light-colored container: I use glazed white ceramics)
And whatever you do, don’t fuss a lot over your Cephalotus: they like to be ignored (well, as long as they are getting proper waterings, of course!) and left alone as much as possible. Oh, and they also resent root disturbance, so if you repot a plant, do it when it is dormant, not during the growing season.