Bio-Domes in Tropical Countries

Last updated 4th Aug 2011

Introduction

As you are reading this, you will probably have a plant already in a Bio-Dome and will be considering what to do next. All the Nepenthes varieties offered for sale in Bio-Domes in tropical countries have one thing in common: They are artificial hybrids bred for their vigour and temperature tolerance so they will grow well outdoors or in the lower temperatures of air-conditioning. You are probably already a plant lover and may have your own ideas for potting your plant on. Firstly, we will give you an idea of the overall range of conditions we are trying to maintain year-round for your plant. Then we will give one example we have tried successfully but there are many other ways. Future updates to this page will contain suggestions for growing-on indoors, as well as in greenhouses. We welcome feedback and photographs which we might use in future updates to illustrate different setups.

If you do not wish to read all the details below, you can go straight to one example of how you can pot your plant using our step-by-step guide.

Temperature

Your plant is either a cross between two lowland varieties, or an intermediate growing variety crossed with a lowland one.  It is newly developed and is amongst the first of a new breed of temperature tolerant Nepenthes. It will be happy anywhere in the range of between about 18 deg C and 35 deg C, although it is better to avoid the extreme ends of this scale for prolonged periods. This means that it’s possible for your plant to be grown outdoors or in air-conditioning so long as it is protected from low humidities.

Light

Nepenthes need more light than many people suppose. They do not naturally occur in dense dark jungle but most forms are fond of open sunny areas. If both humidity and light are correct, the pitchers on your plant should be colourful. If they are pale, small, or do not form at all, the light levels may be insufficient. Too much light may result in burning of older leaves or overheating of the Bio-Dome. New leaves as they develop, will often have a reddish tinge, turning to green as the leaf matures. This is a good indication that there is enough light available.

As a rule of thumb, if using natural light, there should be between about 2 and 4 hours of direct sunlight in the early morning or late afternoon but as you are in the tropics, please be careful not to overheat the Bio-Dome. Dappled sunlight for longer periods is best.

Nepenthes can be grown very well under artificial lights indoors. A fluorescent tube or CFL bulb about 30cm (1’) away from the plant on a 12 hour time-switch works very well and is used by many experienced growers. There are also a range of new LED grow-lights becoming available, any of which can be tried according to the manufacturer's recommendations.

Humidity

One of the primary functions of the Bio-Dome is to provide the high humidity which young Nepenthes all need. However, Nepenthes plants can adapt to lower humidity over time and this is one of the keys to success. Has your plant grown leaves outside the dome? If so, have pitchers formed on the ends of the new leaves? If the answer to both questions is “yes” then you are fortunate in that your plant is already in a place where the ambient humidity is high enough. If you are in a humid tropical country which naturally has high humidity, then you may probably find you can grow the plant easily outdoors without the protective dome. Cities, even in tropical countries often have low humidity at certain times of the day due to the drying effect of hot concrete.  However, these plants can often adapt to this. Misting by hand several times a day always helps if you have the time and dedication.
Growing in air-conditioned environments can also be achieved for many varieties without the protective dome but the plant often has to be given time to adapt. Allowing it to grow new leaves and pitchers through the hole in the top of the dome is one way to achieve this. If pitchers are forming, the humidity must be sufficient.

Potting Media

Most Nepenthes can be grown in a wide variety of different inert potting media. Every grower has his or her favourite but they all have the following properties in common:

• Well drained, containing plenty of air
• Must have no built-in fertilisers (e.g. most proprietary garden-type potting mixes are not suitable)
• Must be neutral or slightly acidic
• Must not contain toxic salts (e.g. unwashed coir products)

The list of possibilities is nearly endless but many will contain one or a blend of the following:

• Orchid bark
• Perlite
• Peat
• Vermiculite
• Chopped coconut husk (coir chips)
• Various types of foam
• Sphagnum moss – live or dried

In order for the mix to be acidic, if neutral materials are used, many people like to use a little peat in the mix. Coir chips are naturally acidic. One favourite is sphagnum moss which is usually supplied dried in packs. It can be used by itself for all Nepenthes we supply in Bio-Domes. Please do not use a propriety potting mix from a garden centre. It will probably contain fertilisers that will be toxic to Nepenthes.

It’s a little-known fact that Nepenthes can be grown very well in nothing but foam. You can include part or all of the foam pad from your Bio-Dome when you pot-on. The example we give in our our step-by-step guide does exactly that.

Fertilising

We will deal with this topic inn a future update. Your plant has fertiliser built in and will catch it's own prey as it grows.

Size and Type of Pot

Nepenthes do not need large pots until they become very large. A pot diameter of 8cm (3”) would be ideal to start with. Since the media must be well drained, a mesh-type pot works well. Sphagnum moss as a growing medium in a mesh or coir hanging basket is a popular choice in greenhouse or conservatory environments.

Watering

The roots of Nepenthes should never be allowed to dry out.  Once the automatic wicking system is abandoned, the plant must be watered daily or as often as necessary to keep the potting media wet.  However, watering using the wick is still a viable option after potting on as our step-by-step guide shows. Rainwater is always best for Nepenthes although tap-water may be used unless it’s very hard.

Containers

You might not even need a container if your plant is happily producing leaves and pitchers through the hole in the top of the Bio-Dome, or you already have a garden with high humidity but in some cases, especially in air-conditioned rooms of cases the plant will need some protection from dry air. The container you house your plant should have the following basic properties:

• Be attractive
• Allow light to reach the plant
• Allow air circulation sufficient to prevent over-heating or condensation.
• Fit into the space available

We have found that most garden centers offer an attractive range of glass containers. Alternatively, glass or plastic fish tanks may be converted into terrariums and used to house collections of Nepenthes.

Some Examples Using Glass Containers

The photos below show some plants that have been successfully moved from their Bio-Domes into such containers and are being kept outdoors on a balcony in the tropics. The same system works well in air-conditioned rooms to protect from low humidity so long as there is sufficient light available. Please follow the link to our step-by-step guide .

Step-by-step Guide

So how can you do this? Find out from our step-by-step guide.

Internet Resources

If you wish to know more about Nepenthes cultivation in general, we recommend you go to the following forums. Not all information on forums is accurate but you may get some good ideas. Here are some prominent forums listed in no particular order:

Carnivorous Plant UK

International Carnivorous Plant Society

Carnivorous Plants in the Tropics

Green Culture Singapore