Over 171 species and counting, Nepenthes, or Asian Pitcher Plants, are far more varied than the American and Australian pitcher plants and are completely unrelated to them. It’s an excellent example of what is known in biology as convergent evolution, that is, two unrelated groups of plants evolving similar mechanisms to meet similar needs. Many have strikingly different lower (rosette) and upper (vine) pitchers.
TRAPPING: While the details vary, Nepenthes employ a combination of nectar and color to attract insects, and slippery surfaces to ensure that they are trapped. The secrete their own pool of digestive enzymes, and most have lids to prevent the liquid being diluted by rainwater. The liquid is also viscous, making it very difficult for prey to escape. A few have even evolved to serve as “toilets” for forest shrews, and one produces a special type of pitcher that has abandoned insect trapping altogether, to serve instead as a bat “hotel,” reaping the benefits of their high-nitrogen feces.
CARE: Nepenthes can be divided into two main groups according to their native habitats: Highland and Lowland Nepenthes. Highland Nepenthes, which grow on mountaintops, require cool temperatures, from 45-65 degrees though many can withstand higher temperatures for short periods. They all appreciate a nighttime drop in temperature. Lowland Nepenthes prefer nighttime temperatures of at least 70 degrees, and daytime temperatures in the 80s and 90s. These can be challenging to provide, but there are also intermediate species and especially hybrids which are much more tolerant of typical home conditions. Four of the easiest are Nepenthes alata, Nepenthes “Ventrata,” Nepenthes “Miranda” and Nepenthes sanguinea, which has many different forms.
SOIL AND WATERING: Unlike Sarracenias, most Nepenthes are not bog plants, preferring a light, well aerated medium. There are as many different combinations as there are growers, but a few that work are: Coconut fiber and Sphagnum moss, Sphagnum moss and orchid bark, live Sphagnum, chunky peat, large perlite and silica sand, bark, sphagnum and wood charcoal, and more. Never leave them standing in water, but water frequently and allow them to drain completely. Nepenthes resent root disturbance, so repot very carefully.
LIGHT: This is the single most important factor in getting Nepenthes to produce pitchers. Bright light from a south or east window, or artificial lighting, both work fine, making them good as house plants. They may stop pitchering during the shorter, darker days of winter.
HUMIDITY: Some more specialized Nepenthes require especially high humidity, but many can grow perfectly well in homes. A terrarium is also an option but remember that many Nepenthes can grow quite large!
FEEDING: Some people use a weak fertilizer solution in the pitchers. It’s best to learn more before attempting to fertilize and go easy at first!