NEPENTHES GROWING GUIDE

Am I getting too much / too little light?

In the first instance, Nepenthes leaves will blush red from light stress but this doesn’t necessarily mean that your plant is getting too much light. For my dimmable lights I will dial it up a little, let the leaves blush red, but then wait to see if the new leaves go back to that nice glossy green. If the new leaves are also showing stress, I’ll dial it down or move them further away from the light source.

Humidity

Nepenthes grow ideally in a high, consistent humidity. In my reading and experience, if you can’t have high and consistent humidity, you will achieve better results acclimating your plants to a consistent lower humidity over a fluctuating inconsistent environment. For this reason, I don’t bother with the advice I read early on about misting your Nepenthes daily or etc. If anything, wetting your leaves regularly is just going to encourage fungal problems.

To raise humidity, trays of water that the plant sits above can be quite effective. Don’t have the plants sitting permanently in water as this can lead to root rot. I’ve seen people use pebble trays, or the sort of plastic inserts that typically come with fridge vegetable organisers. For my indoor plants, I have them in hanging pots with a saucer that sits below the pot. I water them from above until the saucer is almost full, then don’t water them again until the saucer has sat empty for a day. With a well-draining and airy mix this amount of wetness has been successful, and also gives an easy indication of how often to water.

Temperature

Nepenthes species come from a range of climates and each has different temperature ranges. Most hybrids are considered to grow under intermediate conditions but if you cross two lowland or two highland species I’d aim to keep them in those conditions.

Lowland Nepenthes come from the low altitude zones in the tropics where the day temperatures are above 28 degrees and the night temperature is above 20 degrees. The difference in day to night temperatures is generally not greater than around 7 degrees. I’d aim for 30 degree days and 25 degree nights. Most of my losses when I moved to Tasmania at the end of winter were lowland plants.

Intermediate Nepenthes come from the middling altitudes and, unsurprisingly, sit between lowland and highland growth requirements. They are generally much more forgiving, growing in temperatures between 12-30 degrees. I’ve had intermediate hybrids growing in Tasmanian house temperatures during winter (in the low positive digits), but would aim for warmer where possible. If I’m controlling the climate I generally aim for 25 degree days and above 15 degree nights to maintain good growth. .

Highland Nepenthes come from high altitudes in the tropics where the days are warm (at least 22 degrees) but there are significantly cooler nighttime temperatures (10-15 degrees). A temperature drop of at least 10 degrees is considered critical for these species to thrive into adulthood and becomes more important as the plants mature. Often people report that the temperature drop is more important than the starting temperatures, but I aim for day temperatures of 25 degrees and night temperatures of 12 degrees.

Substrate

Nepenthes like airy substrate mixtures, they are not bog plants like many other carnivorous plants and do not want peat heavy mixtures. I grow 99% of my plants in a coco coir chunk and perlite mix – using bigger chunks for larger plants. For smaller plants I use a cocopeat mixture (the same thing but with some peat added). This keeps it a little moister than pure coco coir and perlite. There are some highland plants (e.g. N. hamata and N. villosa) that grow best in mineral based mixtures such as akedama, kunuma, and scoria (a Bonsai-esque mixture). The main commonality with these mixtures are that they remain moist but not wet, allow a lot of air flow to the roots, are resilient to fertilising with, and are hard to overwater in. A great secondary feature of these mixtures is that they are very easy to repot from.

Sphagnum and perlite mixture is very commonly recommended and used throughout the world. I used to grow in it exclusively! It is undeniable that some people grow amazing plants in sphagnum but in my growing conditions I’ve found that it reacts poorly to substrate fertilisation and is a nightmare to hard repot from. It also is harder and harder to find good sources of sphagnum now that the Brunnings line commonly available in Australia has moved to Chinese over New Zealand sphagnum. If you can get good quality sphagnum and are happy with it, I’d recommend a 50 / 50 sphagnum and perlite mixture.

Fertilisation / Additives

If you choose to fertilise your Nepenthes, start with a heavily diluted mix and slowly increase it over time.I love to fertilise my plants and, fortunately, Nepenthes love being fertilised! Historic advice (and you don’t have to rewind the clock very far) was that fertilising Nepenthes would kill them. This advice is probably what led to a lot of people finding Nepenthes slow to grow.

I use orchid style fertilisers for substrate and foliar spray fertilisation and I use pellet style fertilisers for in pitcher fertilisation. I’ve started experimenting with release pellets placed into the substrate, but I don’t have enough experience to recommend this yet. I’ll rotate through fertilising and water only watering to make sure the substrate is getting flushed out periodically and nothing is building up to high levels. For indoor nepenthes, it’s worth putting them in the sink or outdoors occasionally and giving them a good flush out (if you have access to rainwater that’s even better). If you do use a sphagnum or similarly fragile organic mixture, I’d limit substrate fertilising as it will break the sphagnum down quite quickly.

When I get new plants in, I’ll include a liquid root hormone and an additive of Mycorrhizae (beneficial root fungus) in my rotation. By the time the plants get to you they should have happy and established root systems already.