New growth is light green

[swords]

This is not a real "problem" as most of my Neps are terrarium grown and have been slightly lighter in color under artificial lights but I was just cuious as to why the new leaves are lighter green in color than the dark green the greenhouse growth is. I realize it has something to do with sunlight but what is it that causes the lighter color? Need of red light, or blue light, or...?
Can the leaves ever be dark green in the terrarium or with it always be a lighter green?

[Joachim]

I do believe most often light levels are the key to less colourful plants under artificial lights. Even in a dark spot in a greenhouse the light levels are very high compared to typical terrarium setups.

Another factor could be the spectral power distribution of the lights you do use. But this isn't a problem as long the plants do grow well. Even under those yello NaHDL lights (High pressure discharge plant lights - don't know the correct translation) the plants do grow very nicely. Of course the colouration is different to plants grown under sunlight.

When a massive decrease in colouration appears slowly over some leafes it may also be due to a lack of food. The plant may be low in nitrogen or also in Iron (Fe) which the plants do get from the soil. But I don't think this is the case for your plants by now.

Joachim

[swords]

I know plants can yellow with chlorosis when Iron is deficient but I usually add a few drops of liquid trace-element fertilizer when I do my fertilizing flushes. It's most noticeable on my bical which is just unfurling it's new leaf since I purchased it but at least the new leaf isn't burnt on the edges like the greenhouse grown leafs-just not as dark green.

Simply me nit-picking I suppose...

[nepenthes gracilis]

It is most likely your lighting. When I recieved my N.Rajah it was a greenhouse Nep and it was a very dark green, like a pine tree is, and now has gone over the year it's been in the terrarium to a lime-ish green. It isn't goignt o hurt yor plants at all but it telling you they can take quite abit more light than thier receiving right now. But personally, to be on the safe side, feed the palnts that have this problem somthing to eat, like a fly or a ,eal worm or even better than those two a nice juicy cricket!

[Tony Paroubek]

Gosh everything in my Ghouse is red! Well ok not everything.. Some plants just don't produce red pigment.

I don't really grow much in an artificial setup under lights so I can't really say from experience with that. I will say however that plant coloration is usually closely tied to lighting as has been mentioned. I will also add that the new growth on most plants is usually a lighter green as it is expanding rapidly. And only after a couple weeks do they green up. IE it takes a while for the cells to fill up there new large area with chloroplasts. If the leaves remain pale then there might be a problem, but if the plants look healthy and are making nice pitchers then I wouldn't be concerned. A little extra feeding might help as overall green coloration is mostly tied to nitrogen uptake.

So I guess that sorta answers your question.. blue light ie 420-460nm range would be what the chloroplasts are looking for. Red coloration is usually a response to UV range.
Tony

[swords]

Yes, the plants are doing well (nice leaves, nice pitchers)-the N.alata can't be stopped! I could add another blue bulb to my setups if I removed a daylight colored one. I grow mainly in 29 gallon tanks with 4x 20 watt fourescent tubes (so the whole tank top is covered with lights 2=daylight 2=coolwhite).
Perhaps I will try another blue bulb and see how that goes.
I just like that deep dark green!

[Kim]

Certain nepenthes may by their genetic characteristics be lighter green than others. Usually, N. northiana has leaves that are lighter than others regardless of light. I have several varieties of N. maxima. Some have quite dark leaves and others that produce leaves much lighter. Many times plants grown in much brighter lighting conditions also will have lighter leaves. This is quite true with N. ventricosa when grown with quite a bit of sun in Hawaii where all my neps are grown outdoors. I have several varieties of N. rafflesiana, and these too grow in variations of color to there leaves from a lighter green to quite a dark green even though exposed to afternoon sun. Good luck.

Kim