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.
Materials & Methods
Most greenhouses that 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 greenhouses (see temperature, below).
An 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.
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, 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.
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 and foggy weather, some highland species can be grown. Success has been achieved with N. ventricosa, N. alata, and others. The plants should be kept in a moderately sheltered (50% shaded) area, sprayed and protected from frost. Growers in tropical climates can cultivate lowland Nepenthes species outdoors year-round.
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.
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 with few variations will suffice for most species. A suitable potting media for Nepenthes should be well-drained, slightly acidic and poor in nutrients. Most growers prefer to mix their own. A simple well-balanced mix can be made by combining equal parts of organic and inorganic ingredients. 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.
Parameters for Growth
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.
|At Malesiana Tropicals, we have used the following mixtures for our Nepenthes with excellent success:
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. Species with thick waxy leaves are able to tolerate somewhat drier air and make good candidates for windowsill growing (see below). Those with thin, delicate leaves (e.g., N. hamata, N. tentaculata, N. muluensis, etc.) are very susceptible to humidity fluctuations.
The genus is generally divided into two sections, lowland and highland species, according to their altitude of origin and different climatic preferences.
|Lowland Species||Highland Species|
|Natural Habitat||Sea Level to hill forest.
(0-1000 meters elev.)
|Montane forest to alpine scrub.
(1000-3500 meters elev.)
|Temperature in Cultivation||Hot days, warm nights.
(80-95 F or 27-35 C day)
(70-80 F or 21-27 C night)
|Warm days, cool nights
(70-85 F or 21-29 C day)
(50-65 F or 12 – 18 C night)
|Suggested Growing Situation||Hothouse, Heated Terrarium, Outdoors (Tropical Climates)||Greenhouse, Cold Terrarium, Windowsill (see above)|
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.
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 (rainwater, distilled water or reverse osmosis are ideal) as the excess dissolved minerals frequently found in tap water can accumulate in the soil and cause damage to the sensitive roots.
In the wild, Nepenthes 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 odours 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 at less frequent intervals.
The 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 production is a good indication of general plant health; plants are unhealthy or are kept in poor conditions will often fail to produce pitchers. Even healthy plants do not necessarily produce a pitcher on each leaf 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 suddenly drop their pitchers. 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.
Pests & Diseases
Nepenthes are generally pest-free, though a few insects 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. For severe pest problems the use of a proprietry spray may be necessary.
Establishing Your Plants (bare-root plants only)
Pitchersplant takes great care to ship you only the healthiest plants which have been well acclimatized to nursery 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.
|01||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 Pitchersplant immediately and send us a picture of the damaged plants.|
|02||The plants should be potted into an appropriate soil (see above under Soil). The media should be thoroughly moistened before it is used, and then watered again after the plants have been potted. While potting, care should be taken to spread the roots in the pot. 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.|
|03||Newly potted plants are still extremely sensitive because of their recent transplanting and should be handled carefully. Only several minutes in sun or dry air is sufficient to severely stunt or kill a plant at this stage. They should 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 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.|
|04||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 more air circulation. After a week or two the plants may gradually be acclimatized 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 be considered established when they have grown several sets of leaves and pitchers.|