Nepenthes have long been considered
finicky plants that were very difficult to grow and best left to experts. However,
if you have an understanding of the conditions required by the plants they can
be very rewarding. While some species can be challenging to even experienced
growers, others are quite easy given the right environment. Mostly Asian
plants, a few species occur in other areas such as Madagascar and the
Seychelles. Although most species do not enjoy as much sun as their temperate
counterparts, these plants are not usually found in dense, dark jungle either.
Nepenthes are divided into two groups depending on the altitude at which they
grow, which then determines the temperatures they prefer. Those that grow above
3000 ft. are referred to as highland species and include more than half of all
Nepenthes. These plants experience daytime temperatures in the mid seventies to
perhaps the eighties with nighttime lows at least 20 degrees cooler. In rare
instances the plants can even experience frosts. At this elevation mist and fog
is frequent and humidity is high, often 100% at night. Light levels can be very
bright during the day and humidity may not be as high as lower down the
Lowland species are those that are generally found below 3000 ft. in elevation.
Here, daytime temperatures can be as high as the 90's with nighttime lows in
the 70's. Humidity is also high in these areas day and night. Some plants grow
in the open where there is plentiful sunshine while other prefer growing in
more shaded areas. Both types experience frequent rainfall and are not subject
to drying out for any length of time. The most common type of substrate usually
consists of organic material that is both moisture retentive yet very porous
and well drained.
Some lowland species will tolerate cooler temps while several highland types
will do fine with warmer temps. Many can be considered intermediate growers.
Only a handful are considered extreme highlanders with strict temperature
requirements, especially the nighttime drop. This allows the plant to slow it's
metabolism down and without this rest the plant will quickly weaken and die.
The growth habit is the same for both types and consists of two basic life
stages. The first is that of the basal rosette. A ring of leaves is produced at
ground level, each with a pitcher at the tip. These lower traps are generally
short and squat and tend to face toward the center of the plant. Depending on
the species, the rosette can be just a few inches to several feet across. The
rosette stage is the most practical stage for terrarium growing for most
species. After a period of time the plants then produce a vine that can reach a
couple feet to several meters in length, depending on the species. The leaves
on the vine also produce traps however these are usually very different from
the lower ones and are generally more narrow and elongated. The base of these
traps is constricted rather than wide and the pitchers will face away from the
plant. It is not uncommon for a few intermediate traps to be produced between
the upper and lowers that will share characteristics of both.
The first step in choosing which species to grow is to determine what
conditions are easiest for you to provide. If you live in the warm southern
states perhaps the lowland species would be easiest. For those living in the
more northern areas that naturally experience cooler temperatures the highland
growers would probably be a better choice. No matter which you choose, the
basics of culture are quite similar.
Substrate: Nepenthes like an acidic growing media that will stay moist
yet allow for plenty of air circulation around the roots. Peat moss based mixes
are quite popular and are widely used. The main drawbacks to these are that
they break down over time and can wind up rotting the plants roots if not
repotted on a regular basis. They are still very useful as long as they contain
a large percentage of amendments such as perlite, tree fern fiber and fine
grade fir bark to enhance drainage. Some growers prefer to use straight
long-fibered sphagnum moss to grow the plants. We have found that even when
using New Zealand Sphagnum (the highest quality), it can stay too wet for many
species. We are currently experimenting with a new growing mix comprised of 90%
shredded cypress mulch, 5% perlite and 5% peat moss. So far the results are
quite promising. The plants seem to like the excellent porosity of the mix
while being firmly supported by the chunky texture. Additionally, the mix does
not wash out of the pots or disturb the roots when watered from overhead. It is
still too soon to say for sure but so far we are quite happy with it. Each
grower should try several different mixes to determine which one suits his
climate, growing practices and personal preferences the best.
Humidity: Generally speaking, Nepenthes like humidity levels of at least
60% or higher. Some highland species are quite tolerant of lower daytime
humidity levels as long as it climbs overnight. Lowland species are usually
much less tolerant of humidity fluctuations. One symptom of insufficient
humidity is lack of traps. The use of humidifiers or terrarium growing can help
raise humidity to an acceptable range.
Light: Nepenthes are found growing in a wide range of exposures varying
from shaded forest floor to exposed cliff faces therefore it is impossible to
generalize an appropriate light level for all species. Ideally, research the
habitat that your plant naturally grown in and do your best to replicate it.
Additionally, the plant will also give you clues as to the suitability of the
lighting it is receiving. Failure to produce traps is one indication that light
levels or duration need to be increased. This can also be caused by
insufficient humidity. Too much light can cause yellowing of the leaves or red
spots and streaks to appear on them as well. While this does not necessarily
harm the plant it can be unsightly. Reducing light intensity will result in new
leaves emerging a more normal color.
Water: Nepenthes should never be allowed to dry out but will not prosper
if kept too wet. Using a proper substrate will make it much easier to achieve
this balance. Water quality is important but many species do not seem to be as
sensitive to at least low levels of minerals as other types of carnivorous
plants. It is best to allow the water to flush through the pots on a regular
basis and not grow the plants sitting in a water filled tray.