Last weekend I have seen a flowering ! Nepenthes rajah in cultivation in Germany. It took about 15 years for the plant to flower (was a female but there was no male rajah pollen around
( )
Unfortunatly the plant lost all the pitchers during flowering but I have seen some dried ones.
Amazing ! (but they haven't been really big, maybe half of the size of reported big pitchers in nature)
It was grown under "typical" highland conditions.
Some people here in Germany are growing N. rajah without significant temperature drops during nighttime but I have never seen the result with my own eyes.
I have seen some small TC plants "growing" extremly slow under "normal" temperatures inside a terrarium.
I, for myself would rate N. rajah as difficult and very slow !
Even my N. lowii is growing much more faster.
(I must admit that I only own small plants and don't have much experience)
I ! would highly recommend SIGNIFICANT lower temperatures during night. At 20/25°C during summer my plant has grown slower than now 17/25°C.
I believe that 10/25°C would be even better but this is hard to achieve inside a house.
During the end of this summer and autumn I have seen small N. rajah plants growing OUTSIDE (hanging in baskets in an apple-tree) by another grower.
The plants were very hardy but didn't grow fast. (but faster than plants cultivated inside a terrarium under normal tempeartures)
I think that after some accomodation N. rajah can surely withstand humdity drops down to 40-50% during the days (look at the natural habitat !!!!) but nighttime humidity should be surely higher (80% or even more)
just my 2 cents
btw... N. clipeata is a lowland plant ! (can be grown as an intermediate)
My personal list of difficulty for my higland plants is :
starting with the easiest :
alata (maybe ventrata ?), maxima, khasiana, veitchii, inermis, lowii, hamata (only own this plant for some weeks now), rajah, aristolochioides.