Highland plants

[Cindy]

This kind of a stale question since we have growers asking about growing conditions over and over again.

But please kindly bear with me 'cos I really want to grow my N. hamata, macrophylla, ephippiata etc well in typical lowland climate.

1. I have a choice of growing the plants with lights or sunlight. My climate has humidity good enough for ampullaria and bicalcarata to pitcher in a windy spot. What's the highest day temperature and lowest day humidity a typical highland is able to withstand and do well?

2. Cool nights are not possibly here until October. Until then, I need to use a wine cooler. I tried keeping the plants at 100% RH in the wine cooler but have some develop leaf rot (blackening from the tip and moving inwards). I suspect it is due to stagnant air in the wine cooler. I've read that highland neps are less fussy about a drop in humidity and I am considering growing them a little drier to prevent leaf rot. What is the lowest humidity a highland nep can take at night?

3. Why is it that I see that most growers have live sphagnum growing with their highland neps? Does that mean that besides cool temperature, the humidity is although high?

 

[seedjar]

Have you seen this FAQ on Neps on Barry's CP FAQ? It recommends a minimum of 50% RH for sensitive plants. I used to grow all my Neps in partially open terrariums where the humidity would sometimes drop to the 40% range, and my highlanders didn't mind. I'm growing easy ones like ventrata x alata, x. Judith Finn and sanguinea, but I think that shooting for 50% or above for most highlanders sounds reasonable. Keep in mind that young plants - or plants that haven't been hardened off - will be more demanding and may require shade or misting to prevent drying. I give my lowland varieties higher humidity, around 60% in the daytime and up to 80% at night. The Savage Garden recommends a minimum RH of 60% at all times for the genus Nepenthes in whole, which seems fair for terrarium specimens. The writer of nepenthesaroundthehouse.com reports success growing outdoors with RH from 20-70%, although in a favorable warm-temperate coastal climate. nepenthesforeveryone.com agrees with a minimum 50% RH guideline and cautions that plants grown at consistently higher humidity levels are prone to shock from dry air. Michael Catalani, writer of Nepenthes University, suggests a mean RH of 75% coupled with steady air circulation. swords here on the forums says 80% on his site, the Nepenthes House.
Regarding temperatures, Neps Around the House says lows in the 50s and highs in the 80s are fine, given shade when necessary. This seems consistent with the native growing conditions of most highland Neps. My other sources generally concur; the best way to tell is to examine the range of the plant, particularly the altitude of its range. There's a handy index of species with altitudes provided at Nepenthes University. Plants that grow at higher elevations naturally experience colder nights, and typically appreciate them in cultivation.
Sphagnum appears to pop up in the pots of Neps in many terrarium photos here on the forums, but I also see many of the hardier species and hybrids succeeding in conditions that are too dry for sphagnum, so I think that those kinds of conditions aren't strictly necessary. I notice in many photos of Neps in situ that sphagnum is not found. In my terraria, sphagnum doesn't grow well in the Nep pots because I don't water enough - only every week or so. I keep my humidity up with a fogger set to come on for an hour or so five times a day, and sometimes I mist. The Neps seem to love it. Until I get an RO filter and an irrigation setup, I won't really have the water or time to water them more often. I've been able to leave my plants for a week with zero attention and they were none worse for wear, and with regular misting they can go longer without an actual watering.
I hope that helps some. I don't have a ton of experience with all sorts of exotic species, but I did do a lot of research before I started growing the ones I've got.
Best luck,
~Joe

PS - Perhaps this topic should be pinned for reference? That is, if we get some good answers...

 

[Cindy]

Thanks, seedjar. Humidity is no issue to me since my climate is 60-90% RH year old. Light is great as I have good light reaching my balcony where I grow the rest of my lowland and intermediate neps. The only issue is night cooling. I can't afford to cool the balcony but have a wine cooler which I am using to keep the plants at night. For 12 hours or so, the plants do not have much ventilation. I have experience N. hamata suffering from leaf rot in a 100% RH environment.

I just measure the RH in the wine cooler and it is 70-80%. Pretty good eh? I am now wondering if the plants are more forgiving to less air movement for 12hrs in darkness.

I am not too concerned if the live sphagnum grows for me or not. I am keeping the plants on the drier side too, allowing the water in the media to evaporate before the plants go into the wine cooler.

It's an uphill task to grow highlanders here during this time of the year...it's 90s in the day and 90s in the night. It's worse when the humidity is around 80%...

 

[rbjong]

well Cindy, how do you control the humidity? Do you installed a dehumidifier?

 

[Cindy]

Robert, you mean inside the wine cooler? No control. It stabilises around 70-80%.

The plants are in open boxes. But I have to keep a towel inside to soak up water that condensed on the sides.

 

[rbjong]

yeah,inside, but what u are doing seemigly worked.

 

[Cindy]

Yup, worked like 2-3 days. Then I got to clean the inside. A fridge definitely works better but it is too cold. Probably need to think of a way to drain the water faster.