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Question about nepenthes feeding

Hi all:

I don't know if any of you have the answer for this question, but if anybody does, please i am all ears!!:

Assuming one has a nepenthes plant with the correct temperature, light, and humidity: how long can the plant survive without trapping any insects assuming that the plant has no fertilizers in the compost??. has anybody done this experiment??

I don't think they insects to survive... just think of the bugs as vitamin supplements.
To perform the test you would have to grow the plant in sterile conditions (not TC agar as that contains trace amounts of nutrients) and likely aerophonically (in air-out of any kind of planting media). Watering only with distilled water (or as nutrient devoid as possible). Since just about any growing medium eventually becomes host to microbes which degrade the medium and thus create a trace amount of nutrients by their feeding on the breaking down planting medium. Also, any sort of soil usually becomes "alive" with tiny insects like springtails and fungus gnats which eventually make their way into the pitchers, so cutting off any pitchers that would be produced would also have to happen.

If you're willing to go through all that then you would have your answer. As far as I know nobody has done that experiment yet.

Now, all plants require nutrients to survive, no matter what species they are. If they are supplied with only light and water they will eventually weaken and die. Since Carnivores are used to nutrient deficient (not devoid) environments they too need some form of nourishment. Since their environments usually have next to nothing of value to them in the soil they create their traps as an above ground way of obtaining these nutrients. While the traps are technically leaves they could be thought of as leaf/roots since they have a very high number of veins running through the the traps and this is where they are obtaining most of their nutrients.

An interesting experiment many people have done (either accidentally or on purpose) is finding out that fertilizing the soil (and thus feeding the roots) will cause the plant to grow but not pitcher. The pitchers will decrease in size until they no longer form at all. Since the plant has no need to expend the energy to obtain the nutrients from these metabolically expensive to produce traps, it doesn't. In my own experience I can say that N. ramispina will almost immediately quit producing pitchers (even when fertilized only very lightly).

My thoughts anyway!
My plants have been in my terrariums for over a year without catching any plants, or being given any fertilizer.
My plants haven't caught any plants either!
Define fertilizer..

If a plant is grown without ANY nutrients and minerals it will start to show signs of ill health within days. Within a week it will be in sad shape. The biggest reason is the lack of calcium which is used in many cell processes in actively growing cells. IE the growth points. Once calcium is incorporated into the cell it can not be translocated from old plant tissue to new plant tissue. Fortunately most nutrients and minerals are 'recyclable' by the plant. This is what allows them to pull these compounds out of old dying eaves and make new leaves.

Impurities in water, decomposition of potting media and/or impurities within the potting media supply many of the basic elements needed at least to some degree. Usually enough to keep the plant alive at least or increase size at a slow rate.

To really grow however and make steady progress towards a larger cell mass, a plant needs an input of nutrients.

Hi Swords, Tony and everyone else:

Thanks for trying to satisfy my curiosity. Yes, i agree with you all, one will have to deprive the plant of every single nutrient available to know how long it is going to last without nutrients.

It is then feasible to assume, using Tony's explanation that even a novice can keep a nepenthes alive without feeding it at all, given the fact that the plant may use minerals from the water or compost despite the lack of insects in the environment?

Is it then carnivory for pitcher plants a secondary mechanism of nourishment rather than a primary one?

Most people who run a nursery fetilize lightly, or do nothing, as it is not feasable to feed all the nepenthes they have in stock.
People with collections, big or small, have noted good growth from feeding over not feeding(I think Jeff Shafer has mentioned in these forums several times that slower growing highlanders and some others that don't thrive for many seem to get a good burst from feeding crickets and such).
Yes the plants grow with no feeding, but they have evolved to trap insects so with some supplemetation, will do better.


I never used to feed, or I would feed very rarely and while my conditions (light, temp and humidity) were good my plants did not make the size and color of pitchers that they do now. Since the conditions are the same I can really only attribute this to a steady diet. I feed small crickets every two weeks (I mark the calendar so I don't forget) and big ones into the bigger pitchers every other feeding (so as to avoid excess accumulation). I only use crickets because they seem to be the least "rotting" of all the available prey foods. Worms and things have a lot of fat and it's easy to rot a pitcher using them. Crickets are usually quite lean and only will rot a pitcher if it's stuck to the side instead of completely submerged.

I must admit, feeding with insects is the worst part of growing Nepenthes but the plants respond so well to it it's a shame not to.
  • #10
i guess this comes back to the question, will feeding nepenthes fertilizer:
1) produce bigger traps due to the supplus amount of nutrients to sustain a bigger pitcher
2) produce smaller pitchers because pitchers are not needed

and will not feeding nepenthes fertilizer:
1) produce bigger traps to be able to hold and obtain more nutrients per pitcher
2) produce smaller traps due to the difficency of nutrients

and will feeding nepenthes bugs:
1) produce bigger pitchers due to the surplus of food and being able to sustain a bigger trap
2) cant think of a reason to form a smaller pitcher in this situation as if the plant produces a smaller pitcher, less insects will be captured and it will then produce a bigger one

and will not feeding nepenthes bugs:
same as not feeding nepenthes fertilizer

does anyone have a conclusion on this? i would like to know
. Zongyi
  • #11
The large use of very pure water and potting mixes which contain a significant amount of inorganic substrate and little in the way of decomposing organic matter. Leads me to my own personal theory that in cultivation the plants are getting less nutrients than they would in nature via the soil. This makes it even more important to suppliment through feeding. Preferably in some sort of 'natural' fashion with insects and whatnot instead of inorganic fertilizers whenever possible. Remember carnivorous plants grow in nutrient poor environments not nutrient devoid. These environments are capable of growing even noncarnivorous plants reasonably well but the combination of supplimental nutrients via trapping insects gives carnivorous plants an edge to out compete the noncps to some degree.

  • #12
If anyone read Heiko Reischer's CPN article of three years ago, he demonstrated you could use a non-organic potting medium of Seramis, lava pebbles and one other clay pearl substrate that escapes me at the moment. He stated that due to the lack of organic compounds , it was "necessary" to put Osmacote into the mix and add a little more every six months.
I don't think the article mentioned anything about insect feeding, though.


  • #13
In my experience:

will feeding nepenthes fertilizer:
2) + they may eventually stop producing pitchers altogether, some species are more sensitive than others.

will feeding nepenthes bugs:
1) They will only produce pitchers of what their species are physically capable of. You won't get a 25 cm N. dubia pitcher no matter how many insects you feed it.

Not feeding with insects is not the same as not feeding with fertilizer since the effects of feeding with bugs and feeding with fertilizer is different.
Feeding exclusively with fertilizers produces larger leaves and small to no pitchers in some species.

You can feed with a very small amount of fertilizers AS WELL AS insects  to get the best of both results.

Experimentation with your own plants in your conditions is what will solve your questions. Each species responds differently to fertilizers and TYPES of fertilizers. I use Gro More's Urea Free, high Nitrate nitrogen fertilizers so that the minerals are available as soon as they are applied.
For more technical info on the types of fertilizers available check this link out: fertilizers It is written geared towards slipper orchids but since they coexist with nepenthes in many of the same nutrient poor environments the technical information can be useful for the cultivation of both types of plants.