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How to Grow Nepenthes
This page is intended to provide an outline of the methods used for successfully growing Nepenthes, and has been designed to serve as a reference for both beginners and experienced growers alike.
If you are a first time grower feeling intimidated with the prospect of growing these seemingly delicate and specialized tropical plants, you will be delighted to find that most species are surprisingly easy to maintain, and with a little care can even be kept as houseplants. 
Index to Topics
Materials & Methods
Growing Setups
Containers
Soil
Parameters for Growth
Light
Air & Humidity
Temperature
Watering
Maintenance
Fertilizer
Pruning
Pitcher Health
Pests & Diseases
Other Topics
Establishing Your Plants
Troubleshooting Guide
Setting Up a Terrarium
Growing Setups
Greenhouses: Most greenhouses which are already established for the cultivation of tropical plants (high humidity and stabilized temperatures) make ideal environments in which to grow Nepenthes. Due to their different requirements, highland and lowland species are best maintained in separate houses (see temperature, below).
Terrariums: A used aquarium or similar glass tank can make an excellent growing chamber for keeping a small collection of tropical plants and is surprisingly easy to maintain. Nepenthes thrive in the high humidity that a terrarium provides and most species will rapidly outgrow even large tanks. Lighting is best provided by several fluorescent tubes (any broad-spectrum brand works well) positioned directly on the lid of the tank. Complete instructions on how to set up a Nepenthes terrarium will be included in a future article.
Houseplants: An increasing number of plant collectors have been finding that, with proper care, many Nepenthes may be grown as houseplants on sunny windowsills. In addition to catching a few annoying houseflies, a healthy plant with pitchers makes a fascinating addition to the windowsill garden. Those species of Nepenthes which can tolerate relatively dry air and temperature fluctuations seem to perform best indoors. Good candidates include: N. alata (highland spotted form), N. khasiana, N. maxima, N. tobaica, N. ventricosa, and various hybrids. It is very important to insure that plants grown indoors receive adequate light and humidity. Plants should only be kept on bright windowsills which receive a minimum of 3 hours direct sun each day. Additional humidity can be provided by frequent spraying with pure water.
Outdoors: Depending upon local climate conditions, Nepenthes can make suitable plants for the patio or outdoor garden seasonally or year-round. In temperate areas which receive regular cool/foggy weather (often coastal), some highland species can be grown. Success has been achieved with N. ventricosa, N. alata, N. khasiana, and others. The plants should be kept in a moderately sheltered (50% shaded) area, sprayed frequently, and protected from frost. Growers in tropical climates can cultivate lowland Nepenthes species outdoors year-round.
Containers
Nepenthes can be grown in a variety of containers, but plastic pots are generally preferred because they are economical, lightweight, and come in a great range of sizes. Most Nepenthes will do well in a one-gallon pot, but some of the larger species (N. bicalcarata, N. merrilliana, N. sumatrana, others) require containers of 4-5 gallons to reach full size. Seedlings and young plants can be grown in 4-6 inch pots or trays. Clay pots, though attractive, are avoided by many growers due to the belief that they accumulate harmful salts and chemicals. However, experience shows that healthy Nepenthes can be grown for many years in clay pots, especially if they are given high-qualtiy pure water. Containers should always have sufficient holes to permit rapid drainage and good soil aeration. Hanging baskets and pots are an excellent way to display larger specimens, and allows for the trailing vines and tendrils to grow without support.
Soil
In the wild Nepenthes grow on a wide range of substrates ranging from clay soil to mossy tree trunks. Fortunately, it is usually not necessary to duplicate these conditions in cultivation and a single general compost will suffice for most species with few variations. A suitable potting media for Nepenthes should be well-drained, slightly acidic, and poor in nutrients. Most growers prefer to mix their own, and a simple well-balanced recipe can be made by mixing equal parts of organic and inorganic ingredients. Commonly used organic materials include sphagnum moss, sphagnum peat, tree bark, and osmunda or tree fern root fiber. These provide some moisture retention whilst being low in pH and relatively nutrient-free. Inorganic materials such as pumice, perlite, sand, granite chips, and clay pellets help to increase drainage and soil aeration, which is an important factor in the growth of healthy Nepenthes roots. The addition of one part charcoal chips assists in aeration and may aid in preventing stagnant media.
We have used the following mixtures for our Nepenthes with excellent success:
Potting Mix 1
1 part granite chips*
1 part tree fern root fibre
1 parch charcoal (optional)
A very well-drained mix suitable for daily watering and epiphytic species.
Potting Mix 2
2 parts coconut peat**
1 part vermiculite
1 part tree fern root fibre
A good general mix for lowland terrestrial species; high moisture retention.
Potting Mix 3
2 parts sphagnum moss
1 part tree fern root fibre
(optional)
An excellent mix for many highland species. Also good for some lowlanders.
*Pumice, lava rock, or coarse sharp sand may be substituted for granite chips.
**Regular sphagnum peat (peat moss) can be substituted for coconut peat.
In each of the above mixtures, bark or osmunda fibre may be substituted for tree fern root fibre.
Light
Most species of Nepenthes require a minimum of 3-4 hours of direct sunlight per day or about 30-50% greenhouse shade cloth (depending upon local climate). Good lighting will not only enhance the growth of most species, but it will also bring out full coloration in the pitchers and help to stimulate flowering. Insufficient lighting is a common problem when growing Nepenthes, symptoms include large floppy leaves and/or failure to produce pitchers. A few species, such as N. ampullaria, N. bicalcarata, N. hirsuta, N. macfarlanei, N. rafflesiana, and others, prefer somewhat shadier conditions.
Air & Humidity
Being wholly tropical plants, sufficient humidity is a key factor in the health of Nepenthes foliage. Generally it is recommended to maintain the humidity at a minimum of 70%, which can be accomplished in non-tropical climates by frequent misting or growing the plants in a greenhouse or terrarium. Some species with thick waxy leaves are able to tolerate somewhat drier air - these make good candidates for windowsill growing (see below). Others with thin delicate leaves (N. hamata, N. tentaculata, N. muluensis, etc.) are very susceptible to humidity fluctuations.
Temperature
The genus is generally divided into two sections, lowland and highland species, according to their altitude of origin and different climatic preferences.
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Lowland Species
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Highland Species
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Natural
Habitat
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Sea level to hill forest.
(0 - 1000 meters elev.)
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Montane forest to alpine scrub.
(1000 - 3500 meters elev.)
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Temperature
in Cultivation
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Hot days, warm nights.
(80-95 F or 27-35 C day)
(70-80 F or 21-27 C night)
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Warm days, cool nights.
(70-85 F or 21-29 C day)
(50-65 F or 12-18 C night)
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Suggested
Growing
Situation
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Hothouse
Heated Terrarium
Outdoors (Tropical Climates)
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Unheated Greenhouse
Cold Terrarium
Windowsill (see above)
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Due to their different temperature requirements, it is usually necessary to cultivate lowland and highland species separately. A few highland species (N.fusca, N. maxima, N. veitchii, etc.) can be considered "intermediate" plants, and at least some varieties of these can be successfully grown along with lowland species.
Watering
Nepenthes appreciate frequent watering and the soil should never be allowed to become dry. Watering can be done on a daily basis (in warm temperatures), or once every 2-3 days during winter. Pots should never be left in standing water as this will quickly suffocate the roots. Clean, pure water should be used whenever possible (reverse osmosis, distilled, or rainwater are ideal) as the excess dissolved minerals frequently found in tap water can accumulate in the soil and cause damage to the sensitive roots.
Fertilizer
In the wild, Nepenthes are able to thrive in nutrient-poor soil largely because they are capable of supplementing their diet with insect prey. Though it has been shown that plants in cultivation can survive for many years without "eating", growth can be greatly enhanced by regular feeding. In some situations, such as outdoors or in the greenhouse, the plants may capture a sufficient number of insects on their own. Many growers prefer to feed insects to the pitchers by hand; in this case frozen crickets or mealworms (available at pet food stores) are often used. Care should be taken to avoid an excess amount of prey in the pitchers, as this can lead to bad odors and death of the pitcher. Usually a few insects per pitcher is sufficient. Foodstuffs such as meat and eggs can lead to rot.
As an alternative to feeding with insects, Nepenthes may be given artificial fertilizers. A variety of brands can be used, but those with a high nitrogen content and full micronutrients give the best results. Fertilizer (usually diluted to 1/4 normal concentration) can be applied directly to the soil once monthly to mature, actively-growing plants. Young plants or slow-growing species (especially highlanders) should be given a more dilute solution and/or at less frequent intervals.
Pruning
The natural vine-forming habit of most Nepenthes species necessitates regular pruning if the plants are to be kept in good form. Pruning can be performed year-round in tropical areas, or in spring when the plants have resumed active growth. Generally, most or all of the long climbing stems can be trimmed back; this will encourage the development of new robust basal shoots and stimulate the formation of lower pitchers. It is important not to remove all the leaves, as there needs to be sufficient foliage remaining for the plant to recover vigorously. Plants which are cut back completely to the soil will often die.
Pitcher Health
Large healthy plants with flushes of colorful pitchers are the pride and joy of any Nepenthes collection. Pitcher production is a good indication of general plant health; plants which are unhealthy or are kept in non-ideal conditions will often fail to produce pitchers. Even in healthy plants, each leaf does not necessarily produce a pitcher, and some species appear to produce pitchers only in intermittent flushes. Pitcher formation can be encouraged by good lighting and high humidity. In some species, upper pitchers are more regularly produced on tendrils which have actively coiled around an object.
Though there is some evidence to indicate that water-stressed plants are capable of reabsorbing moisture from their pitchers, severely dehydrated plants may drop their pitchers suddenly. Developing Nepenthes pitchers will secrete their own fluid, and it is usually unnecessary to add water to them as this may dilute the contents and render them ineffective for digestion. Exceptions can be made for those species with reclining lids such as N. ampullaria and N. lowii, or if the pitcher contents have been accidentally spilled.
Depending upon the species, individual pitchers may last anywhere from 1-8 months. Senescing pitchers will usually brown in their top half first, and they can remain in this half-withered state for several months. These are still beneficial for the plant and should not be trimmed until they have completely browned.
Pests & Diseases
Nepenthes are naturally quite pest-free, though there are a few insects which will sometimes present problems in collections. Wherever possible it is best to remove pests by hand rather than treating with insecticides, as frequent use of some chemicals can result in severe damage to the plants.
Thrips are a common pest in many cool greenhouses and will occasionally attack Nepenthes, though they seldom occur in sufficient numbers to present a serious threat. They can be found most often on the undersides of the leaves near the midrib, and can easily be removed by regularly wiping the leaves clean. Scale, which are often introduced to the plants by ants, can present a much more severe problem. Though scale can sometimes be kept in check by diligent hand-picking, infested plants may need to be treated with an insecticide. In this case, mild doses of Malathion have proven effective and not particularly harmful to the plants.
Most fungal infections on Nepenthes such as sooty mold are easily removed by manual cleaning or treatment with a mild fungicide (such as diluted benomyl). Leaf-spot fungus, which is a common problem in some species especially when grown in bright sunlight, can be effectively treated with thiophanate-methyl.
Establishing Your Plants
We take great care to ship you only the healthiest plants which have been well acclimatized to greenhouse conditions and are actively growing. However, it is unavoidable that bare root plants will undergo a certain period of shock after shipment due to the handling of the roots. After you first receive your plants, the following steps should be taken to ensure a minimum of transplant shock so that they may quickly resume rapid growth.
1. Check all the plants thoroughly upon arrival. If there are any which have died or been severely damaged as a result of shipment, please notify us immediately.
2. The plants should be potted carefully into an appropriate soil (see above under Soil). The media should be thoroughly wet before it is used, and then watered again after the plants have been potted. While potting, care should be taken to place the root systems so that they cover the maximum volume of space within the pot; bunched root systems may benefit from being delicately spread apart. In any case, be sure not to damage the roots during this process as this may stunt or kill the plant. If possible, potting the plants should be done in a cool shady area to ensure that the leaves and roots will not become dry during the process.
3. Although the plants may look very nice once they have been potted, they are still extremely sensitive because of their recent transplanting and should be handled delicately. Even several minutes in sun or dry air is sufficient to severely stunt or kill a plant at this stage. They should thus be immediately placed in a suitable environment for their establishment. The vital factors here are: moderate temperatures (22-27 C), moderate light (60-80% shading), and very high humidity (90-100%). Placing plastic bags or clear containers over the plants is an easy way to provide this environment, but care should be taken to ensure that the temperature does not rise excessively. A terrarium can also be modified to serve this purpose easily. The plants can be placed in a more open position in the greenhouse only if they are given frequent misting.
4. The plants should now be watched carefully for new growth. If conditions become too stagnant, you may notice fungus or algae on the surface of the soil. This is not usually a problem, but can be treated by giving the plants a bit more air circulation. After a week or two, the plants may gradually be acclimatised to a more normal environment for their growth. After a month or so, the plastic bags may be removed entirely and light increased. At this point you can begin to treat the plants according to the usual cultivation requirements listed in the section above. The plants can truly be considerd "established" when they have grown several sets of leaves and pitchers.
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