Cultivation

GENERAL CULTIVATION TIPS 

CLIMBING PITCHER PLANTS (Nepenthes species and hybrids)
Climbing Pitcher Plants can have a reputation of being difficult plants to grow. In most cases, however, this is a reputation that is not warranted. If the proper conditions are supplied, Climbing Pitcher Plants will not only survive, but thrive. If you are starting out it is recommended that you try one or two species/hybrids to ensure your plants are happy before you expand. To decide which plants best suit your climate we need to look at plant hardiness zones. I’ve also listed some commonly available species/hybrids that will grow well in each particular zone.  

Plant hardiness zones  

ZONE 1 (Alpine) – N. maxima (Highland) N. sibuyanensis, N. rajah, N. maxima x ventricosa, N. sibuyanensis x maxima. *Note that any plants grown in this zone will need to be grown in a glasshouse heated to ensure temperatures do not drop below 0°C.  

ZONE 2 (Cold Temperate) – N. maxima (Highland), N. sibuyanensis, N. aristolochioides, N. maxima x ventricosa, N. sibuyanensis x maxima, N. lowii x ventricosa red. *Note that any plants grown in this zone will need to be grown in a glasshouse heated in winter to ensure temperatures do not drop below 0°C.  

ZONE 3 (Temperate) – N. maxima (Highland), N. sibuyanensis, N. alata, N. maxima x ventricosa, N. sibuyanensis x maxima, N. lowii x ventricosa red, N. ‘Lady Pauline’.  

ZONE 4 (Warm Temperate/Sub Tropical) – N. maxima (Highland), N. alata, N. ventricosa, N. maxima x ventricosa, N. sibuyanensis x maxima, N. lowii x ventricosa red, N. ‘Lady Pauline’. 

ZONES 5-7 (Tropical) – N. ampullaria, N. mirabilis, N. rafflesiana, N. alata, N. ventricosa, N. x ventrata, N. x hookeriana, N. x tricocarpa  

Obviously, the trick is to provide an environment similar to the conditions the plants grow in habitat. When one takes into consideration the fact that Nepenthes grow in habitats ranging from lowland swamps, exposed rock faces, moss-covered mountain summits, rainforest floors, treetops as epiphytes and within mangrove swamps, this task may seem daunting. However, there are some basic principles that can be applied to most of the 130 odd representatives of the genus.  

Basic requirements of the plants can be divided into the following;  

HUMIDITY  

TEMPERATURE  

LIGHT  

WATER  

SOIL  

POTS  

FERTILISATION  

HUMIDITY

Humidity is very important for the formation of pitchers (traps). In fact, Humidity is more important than temperature. I recommend that humidity be maintained above 50% for as long as possible. Plants will certainly survive below this but they will struggle to produce traps. If you live in a climate where humidity is low for extended periods, some artificial means of supplying humidity for the plant will be beneficial. This may be something as simple as a regular misting for indoor plants, to housing your plants in a greenhouse (or on a small scale, in a terrarium). Avoid placing your indoor plants near air conditioners. A bright bathroom or kitchen may be better.  

TEMPERATURE


Climbing Pitcher Plants can be roughly divided into 3 groups. Lowland species, which grow at an elevation from sea level to about 500m ASL, lower montane species, growing between 500m and 1000m ASL and highland species, which grow from 1000 to nearly 3000 m ASL. Of course, there are several representative species that cross these divisions, and the growing conditions best suited for the plant in cultivation will be dependant on the location of the wild population from which it was derived. For example, N. maxima occurs from the lowlands of Sulawesi and Papua to over 2000m ASL. You can find representatives of this species in Australia suitable for all zones. See notes on this species for further information.  

Lowland species
Plants that have originated from lowland conditions require high temperatures, as would be found in a tropical climate. Daytime temperatures of 25-40°C, with nighttime temperatures dropping no lower than 15°C are ideal for these plants. Depending on the species, they will tolerate temperatures outside of these parameters for limited periods if humidity levels are maintained above 70%. If you live in a tropical or sub-tropical climate, it is possible to cultivate lowland Nepenthes without any special requirements such as heating or greenhouses. ZONES 5-7  

Lower montane species
Also known as intermediate plants, these will tolerate somewhat warmer temperatures than highlanders, but still appreciate it a little cooler than true lowlanders. ZONES 3-5  

Highland species
All Climbing Pitcher Plants are tropical plants, their habitat restricted to areas of high rainfall and humidity. It therefore comes as a surprise to some that there are species that require cooler temperatures to survive. These are the highland species, and are found on the higher slopes of equatorial mountains, where moss forest can be found. Weather conditions on these mountain summits can be extreme, with exposure to high winds and extremes in temperature. Depending on altitude, plants can be exposed to temperatures of around 25 C during the day to near freezing at night. In cultivation, daytime temperatures can be higher if night-time temperatures drop to the vicinity of at least 15 C. Obviously, the higher the altitude a plant is located, the lower the temperature required for healthy plants. Higher summer temperatures can be tolerated for short periods if humidity is maintained above 70%. These plants are ideally suited to people who live in temperate climates. However, it should be noted that very few species will tolerate temperatures dropping below freezing, or exposed to frost. If you live in zones 1 and 2 you will need to keep your plants indoors whether it be in a heated glasshouse of inside your home. ZONES 1-4   

Hybrids
Climbing Pitcher Plants hybridise readily. This has led to the development of many interesting and beautiful plants. Hybrids can generally provide a more tolerant and hardy alternative to species. They are often more vigorous and more tolerant of hash treatment.  

LIGHT  

Most species of Climbing Pitcher Plants grow in bright conditions often in full sun.   

The majority of Climbing Pitcher Plants enjoy exposure to partial sunlight, and some can be hardened to full sun exposure. In cultivation, this can be achieved by either growing the plants in an outdoor position where they are partially exposed to sunlight, such as in a courtyard or veranda, or alternatively, underneath a shade cloth or other greenhouse material. We have found that if a material cover is used, it is best to use 30-50% shade cover.  

Of course, there are exceptions to the rule in every instance. Species such as N. sumatrana, N. longifolia and N. adnata prefer much more shade, being found in thicker vegetation. N. bicalcarata and N. ampullaria can be grown well in either full sun or deep shade.  

WATER


Carnivorous plants have a reputation of being sensitive to chemicals present in water. Luckily, Climbing Pitcher Plants are not as fickle as other genus of carnivores. They will tolerate higher levels of chemicals with little effect, within reason of course! Most tap water is suitable for watering (except S.A.), but if rain water is available, all the better.  

The amount of water given to your plants will depend on humidity levels and media used. Ideally, the soil should remain moist, but not waterlogged. If you are using an overhead misting system, this will help maintain humidity, but make sure enough water is making its way into the pot to wet the soil sufficiently.  

Generally, Climbing Pitcher Plants do not like having waterlogged soil. This can lead to root rot, and once this starts, the plant is in trouble. Some growers recommend growing plants like N. ampullaria and N. mirabilis in very wet soil. We grow these plants in exactly the same water conditions to other species, with no ill effects to the plants. Nepenthes rowanae, N. tenax, N. vieillardii and members of the N. thorelii complex do benefit from a few dryer months (typically winter).  

With large pots or hanging baskets, it may be advisable to use the tray method to ensure that the soil remains moist. If this method is used, the plant will do well if the water is allowed to evaporate completely from the tray until more is added. This will help stop the soil becoming waterlogged.  

In summary, ensure soil conditions are moist, not waterlogged. This is achieved by a combination of exposure to water, and the type of soil used.

SOIL


There are many soil mixes recommended to use as media for growing Climbing Pitcher Plants. To be successful, there should be a balance between holding moisture, and allowing aeration of the soil. We basically use 5 soil types for all species we grow.

  1. 50% Coir peat / 50% pearlite
  2. 50% Rhododendron potting mix / 50% pearlite
  3. 50% Sphagnum moss / 50% pearlite
  4. 100% Sphagnum moss
  5. 100% Coir chips (small)

 

Fine Coir and perlite

Rhododendron potting mix and perlite

Sphagnum moss and perlite. Note the thriving Nepenthes root system

Live Sphagnum moss

Coir chips

 
 
 
 
 
 
 
 
 

 

  
 
 
 
 
 
 
 

 
The first two mixes are easily obtained from major garden centres and provide a good all purpose mix for many species and hybrids. The second two are great for highland species. The live moss provides a healthy, relatively pathogen-free, light and aerated media that Climbing Pitcher Plants love. Epiphytes also thrive in Sphagnum moss. Straight Coir chips can be used for most species and hybrids and allow you to fertilise regularly without risk of the mix breaking down (like Sphagnum does). We have only been using this mix for a couple of years so whether it is a good long term solution is yet to be seen. N. ventricosa and its hybrids certainly grow well in this mix.  

Whatever soil you choose, remember that the important thing is that the roots have aerated soil.

POTS

We have found the choice of pots to be relatively unimportant in lowland plants. We use 140mm or 300mm plastic orchid pots. If you can’t get orchid pots it’s a good idea to poke extra holes near the middle of the bottom of the pot with a hot rod or drill to provide extra drainage.For highland plants, it may be a consideration to use terracotta if temperature is likely to be a problem. The cooling effect of evaporation from the clay may cool the soil by several degrees. Otherwise 140mm – 300mm plastic orchid pots will do the job.

FERTILISATION


This is a hotly contested topic in relation to carnivorous plants. Basically, the argument stems from the fact that the plants can catch their own nutrients. Our plants are in greenhouses which have their own little ecosystems, and they do catch quite a lot of prey. Mostly, this consists of ants, flies, spiders, cockroaches and even small lizards (Sunskinks).Some conditions may not lend themselves to being so rich in insect and animal life to supplement the plants growth from natural sources. So this leaves the grower with two options.Firstly, they can add insects such as crickets to the pitchers by hand. This is good practice, but don’t over fill the pitcher with prey, or put in something too big, as this will foul the fluid, and if it doesn’t prematurely kill the pitcher, it certainly won’t smell too good. Don’t spray flies and put them into the pitchers, for obvious reasons. And don’t be tempted to drop pieces of mince, or steak or sausages and the like into the pitcher either. Restrict your supplementing to tasty little insects, and your plant will appreciate your efforts.Secondly, a fertiliser can be used. The trick is not to use too much. If too much is applied, the plant will stop pitchering, as there is no need to supplement its nutrient requirements. This leaves you with a rather unimpressive vine, and the memory of what your plant looked like once upon a time. If this does happen, stop your fertilisation program until the pitchers return. We have found that a weak epiphytic fertiliser, such as Aquasol or Miracle Grow, applied at quarter strength, on a monthly basis, is sufficient to promote plant and pitcher growth.

IN SUMMARY


In a nutshell, find out the temperature that best suits your plant, and make sure you can provide something similar. Ensure your soil medium is moist, but not waterlogged, and is fairly light and aerated. Ensure your plant gets enough light. Remember that hybrid plants are often more hardy than both parents (hybrid vigour) and can be more tolerant of extremes in heat, humidity, light and water. Most importantly, as with a lot of things, don’t be afraid of trying different approaches. Gather as much information as you can, and find out what works best for you. Our growing conditions differ from someone 5 minutes down the road, and what works for them, might not work for us. So use these growing tips and basic principles as a guide, and piece together what suits you and how you intend growing your plants. 

Climbing Pitcher Plants  can be very easy and rewarding plants to grow, and with a little help, can be grown successfully in a wide range of climates.