Question
QUESTION: I have a N. Maxima of an unknown hybrid.  I am growing three of them in an aquarium with a humidity meter inside it.  I am placing it near the window and it gets a  lot of dappled sunlight each day.  My potting mix is 50/50 perlite and peat with a top dressing of long-fiber sphagnum.  Someimtes I open the window to let some air in for cirulation and I mist my plants with filtered water.  Unfortunately only one of my plants is starting to grom new leaves and is growing one pitcher.  It is growing a little slow, but my other plants are not growing at all.  Can you tell what the problem is?

ANSWER: Hi Jake,

The problem is most likely insufficient light intensity.  Overall, Nepenthes need very bright light, especially any of the maxima hybrids.  We have found that N. maxima grows best in partial sun.  In some instances, it can even be grown in full sun.  This species also adapts well to many home conditions, and the use of a terrarium is unnecessary.  I grow many varieties of Nepenthes, including maxima hybrids, in my home without the use of a terrarium or misting.

Dappled sunlight may not be enough for your plants.  Increase the light intensity so they get direct sunlight for about 4 hours each day and very bright filtered light for the rest of the day.  Light is very important for these plants, much more so than humidity.  Nepenthes maxima hybrids are capable of adapting to lower humidity, but they are not capable of adapting to low light conditions.  What you might think is bright light may not bright to your plants.  In the end, it is your plants that are the final judge of what is bright enough.

So the bottom line is to increase your light intensity.  Grow your plants in an unobstructed south or west window.  As you increase the sunlight, you also run the risk of baking them in your terrarium, so you may need to remove them from the enclosure.  This is fine since your plants will adapt to the lower humidity.  Give your plants a month or so to adjust.

If you need further assistance, please write back as a follow-up.  I know the concept of doing away with the terrarium can be scary and difficult, so I recommend that you read up on some of our responses to previous questions about terrariums.

Good growing!
Jacob Farin

---------- FOLLOW-UP ----------

QUESTION: yes, i have sometimes used direct sunlight, but have been noticing some burning on the leaves so I have switched to dappled light to decrease exposure.  And these lights have been coming from a south window too so I think my plants are getting lots of lights.

Answer
Hi Jake,

If you're certain about the lighting, the next area to investigate is the soil.  You mentioned that you're using 50/50 peat moss and perlite, topped with sphagnum moss as a top dressing.  This mix is OK for Nepenthes.  It's not a great mix.  It's just OK.  It is, however, and ideal mix for Sarracenia, Drosera and flytraps.

Nepenthes require a bit more oxygen in the soil than other carnivorous plants.  For this reason, we opt for coconut husk. It retains water while still providing excellent aeration.  You can achieve similar results with peat moss and perlite by simply increasing the ratio of pertlite.  Try using 2 parts perlite and 1 part peat moss.

With this change, you should see some improvement of growth within 2-3 months.  It's a long time, but these plants grow a bit slower than regular plants.

On a side note, I still think you should try increasing the light intensity.  Nepenthes maxima hybrids can tolerate direct sunlight once they are properly acclimated.

The initial burn on the leaves is a sign that the plants were growing in a sheltered environment.  Think of it like going to the beach for the first time in summer.  If you're not used to being in sunlight, you will get a serious case of sunburn.  But by the end of summer, your body will be used to being in the sun, so you won't get burned anymore, or at least not as much.

The same is true with plants.  It's common and many times unavoidable for plants to develop some burning when exposed to sunlight for the first time after growing in a sheltered environment.  However, all new growth from that point onwards will be perfectly acclimated to sunlight.

So give that some thought.  In the meantime, go ahead and change the soil mix to improve the aeration.

Good growing!
Jacob Farin