FlytrapCare Carnivorous Plant Forums

Hi all. Anybody got any thoughts as to the cause of the red/brown blotches. The plant is a Nepenthes rafflesiana. It's grown outside under 70% shade cloth. It has only appeared as we enter the cooler months. The Nepenthes bicalcarata next to it does not have the same problem.
I've included last years climate for July as extra info. July is the coolest month.

That's kind of my thoughts. I'll probably leave it, but observe, as it's not the first time I've come across it. Previously on a N. aristolochioides that used to have to deal with >40*C (105*F) and <5% humidity during summer but would grow like a weed during the cooler months.

Oedema most likely. Their roots taking up more water than leaves can transpire (due cooler temperatures or/and lack sunshine or/and rain seasons).


Here my nepenthes mirabillis var. echinostoma during rain season (too much water, always high humidity, lack heat & sunshine because cloud/overcast). And it always gone after rain season passes (new leaf don't have those blotches). They're like water but also want heat.

Thanks for the informative reply (I had read your other post regarding this, on Reddit). I think the cooler temperatures is the possible culprit. Humidity has dropped now we're in the dry season and sunlight has increased because of reduced cloud cover ( alot of my plants (not neps) get quite leggy under the heavy shade cloth and cloud cover during the wet.)
I'll watch and learn over the next year.

Currently sun in the Northern Sky, so sunshine are weaker at your place now. And plus 70% shade clothes.


As for cooler temperatures (in tropic settings), n. rafflesiana are actually quiet capable growing in relatively cooler temperatures (as in cool intermediate or highland conditions).

Good point. I will be able to improve the lighting as half the shade house is at 50%. Enough light to grow cucumbers and tomatoes even at this time of year. The shade house is used because during the drier months we get smashed by the trade winds and the months leading up to the wet the sun is quite harsh under the cloudless skies. Also the huge grasshoppers can be a big problem, causing a lot of damage in a short period of time. Evident in the first image.
It will be interesting to see the effects of the extra light. One thing I have been casually observing over the last eighteen months is using the phone app 'photone' to give a reference to PAR. Not so much after the accuracy but the relative light levels.
Originally I was growing the plants under a tree and using the phone app it 'appears' it was as dark as Hades under there. 70% shade the plants improved heaps, so 50% will be interesting.
Apologies for the long waffle but I think you have come up with some good advice/information that I can play with. Thanks.