No terrariums. No myths. No nonsense.
The Asian pitcher plant, or Nepenthes, grows naturally in the tropical regions of Asia, predominantly Thailand, Malaysia, Philippines, Indonesia, Singapore, and New Guinea. They occur in a variety of habitats, from the cool misty rainforests high in the mountains to the warm open grasslands at the foot of the mountains.
Growers will separate Nepenthes into two distinct groups: lowlands and highlands. The lowland Nepenthes are those that are native to areas below 3,000 feet. Conversely, the highland Nepenthes are those that are native above 3,000 feet. Growers do this to have a frame of reference on how to cultivate these plants outside of their natural habitat. Those coming from lowland regions often require warm night temperatures, while those coming from highland regions require cooler night temperatures. These terms are quite arbitrary and don’t really account for the vast spectrum of these plants. Therefore, you may also hear terms such as intermediate (plants that straddle the boundaries of lowland and highland), ultra lowland (plants that grow only at very low elevations) and ultra highland (plants that grow above 6000 feet).
Surprisingly, the vast majority of Nepenthes is easy to grow in cultivation and will easily adapt to most homes. Only a small handful of the 80 or so species actually require the controlled environment of a terrarium. If you are new to growing Nepenthes, start off with the easier species that grow well as a houseplant. Avoid using terrariums whenever possible as they often pose more problems than solutions.
Below are some of the common species and hybrids you might find in cultivation:
While there are certain idiosyncrasies that vary from species to species and hybrid to hybrid, the following guide applies to the vast majority of Nepenthes you might encounter in cultivation.
Where to GrowThe vast majority of Nepenthes adapt very well to the lower humidity of most homes. No terrarium is required for vast majority of Nepenthes. Simply grow your plant in a bright sunny windowsill. You may also grow it outdoors if the outdoor temperatures are warm enough. See below for temperature requirement.
A very small handful of Nepenthes might need bit more humidity than what’s found in most homes, so a terrarium may be beneficial. However, the disadvantage of using a terrarium is that your plant will quickly outgrow it. You will then be faced with the difficult prospect of having to acclimate a large plant to lower humidity if you are unable to find a terrarium large enough to accommodate it. Terrariums are also a breeding ground for fungus and mold. You will also need to invest in strong fluorescent lights to replicate the proper sunlight intensity. (Those 20-watt fluorescent tubes are NOT sufficient for Nepenthes and most carnivorous plants.) If you lack experience keeping plants alive outside of a terrarium, you will have worse luck trying to keep one alive inside a terrarium. So avoid terrariums whenever possible. Even in less than optimal humidity, your plant will still grow, but it will produce shorter leaves and fewer pitchers.
TemperatureNearly all species of Nepenthes appreciate prefer daytime temperatures of 65° - 80°F (18° - 27°C). Highland Nepenthes prefer nighttime temperatures of 45° - 65°F (7° - 18°C). If night temperatures are too warm, they will produce smaller leaves and grow much slower. Lowland Nepenthes, however, prefer warm temperatures at night, preferably above 70°F (21°C). Some lowland Nepenthes will adjust OK to cooler night temperatures, but they will slowdown considerably and become prone to brown spots on their leaves. Regardless of the type of Nepenthes you’re growing, protect your plant from temperatures below 40°F.
SunlightThe amount of sunlight you need to provide your plant depends heavily on the species. Some Nepenthes require a lot of sun to maintain to produce their beautiful pitchers. In their native habitat, they grow in the upper canopy of the rainforest. With these plants, grow them in a location where they can receive partial sun. An ideal location is a window that gets four or more hours of direct sunlight and very bright filtered sun during the rest of day. Their leaves will darken a bit when grown in sunlight. This is normal and part of the characteristics of this plant. Other Nepenthes grow in the lower canopy of the rainforest. With these plants, grow them in bright filtered sunlight throughout the day. If their leaves burn or turn yellow, decrease the light intensity. Regardless of the species, avoid full shade.
Artificial LightsIf a sunny window is not possible, use a couple of 40-watt fluorescent tubes or compact fluorescent bulbs of similar output. Keep the light source approximately 8 inches above the plant. The light should be on for 14 hours during spring and summer, and 12 hours during fall and winter. Avoid using incandescent bulbs. They produce too much heat and the wrong type of light spectrum. Even incandescent “grow-lights” are inappropriate for carnivorous plants.
WaterKeep the soil damp at all times, but avoid keeping it in standing water, which will cause root rot. Unlike other carnivorous plants, Nepenthes will tolerate hard water (up to 200 parts per million) with almost no adverse effect. Mare sure the water drains through the soil completely.
SoilFortunately Nepenthes adapts well to a wide range of soil mixes. Many growers have their own secret recipe, but as long as the soil is relatively low in nutrients and provides excellent drainage and aeration, whatever mix you create will be just fine. A popular mix is 1 part dried sphagnum moss and 1 part perlite (or pumice). You can also use 1 part peat moss, 1 part perlite and 1 part silica sand. For additional soil recipes, watch Grow Carnivorous Plants DVD, Volume 3.
FeedingAlthough some growers like to feed their pitcher plants, it is not necessary. Insects live in most homes, and they will naturally be attracted to your plant. Keep in mind that carnivorous plants have adapted to survive on miniscule amounts of nutrients. An adult plant needs only a couple insects or so per month. If you choose to feed your plant, use recently killed insects that will fit comfortably in the pitchers. Avoid putting too much inside because the pitchers will rot.
Do not feed your plant meat. Use insects only. Feeding is not required during the winter months when growth naturally slows down.
If you prefer, you may spray your plant with a weak solution of fertilizer. Use a high quality orchid or bromeliad fertilizer, and use only 1/4 to 1/2 teaspoon of fertilizer per gallon of water. Mist your plant with this mixture. Apply the fertilizer weekly during spring and summer, and only once a month or not at all during the winter when growth naturally slows down.
When it comes to feeding or fertilizing your plants, it is very tempting to over do it. Keep in mind that none is better than too much.
RepottingFor robust pitcher plant, repot it every couple years. Change the soil, and if necessary, use a larger pot. Changing the soil improves root aeration and strengthens the health of your plants. Repotting can be done at any time of the year.