I reccomend misting the plants at least once per
day, preferably in the evening as highland varieties enjoy cool, humid
nights. If possible, keep the door to the bathroom closed to avoid
drafts and dry air. You can actually hear the plants sighing in content
every time you take a hot shower or bath. Just be sure to air out the
room every once in a while or the paint will start to peel from the
walls. Once, during a severe spell of nepenthes fever, I got over zealous
in my humidity upkeep and a nice crop of mushrooms sprouted from the
floorboards. Daytime temperatures are usually in the 70's but this
varies greatly with the time of year. During cold winter spells I've let
the temperature drop to as low as 40 degrees with no ill effects other
than slow growth.
I have also had good luck growing N. ventricosa outdoors. This
species, though quite tolerant of low humidity and temperature, seems to
require high light levels for good growth. In fact, I have noticed a
general trend in that species with narrow leaves (such as ventricosa and
gracillima) tend to require more light than species with broader leaves
(such as maxima and khasiana) which can be moderately shade tolerant.
The only plant that I have had problems with is N. fusca. It
produces fine leaves but grows slowly and refuses to pitcher. I suspected
that it preferred cooler temperatures and higher humidity but a clone of
the same plant in an ideal highland nepenthes greenhouse is doing no
better. Recently, I inspected the growing medium (mostly NZ sphagnum
moss) and found a thick network of fungal mycelium which may be affecting
the plant's growth. According to Cheers' description, the plants grow
naturally in "full sunlight between rocks, often in very dry soil".
Nevertheless, I am a bit apprehensive about repotting mine in a bed of dry
gravel. I would be interested in hearing from others who have had experience
with this plant.
Good Growing,
Ch'ien