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Root feeding nepenthes with osmocote?


Sorry if you ahve gone over this already, but its something I see done so rarely, and even more rarely done well, that I am just to darn curious?

What flavor of Osmocote do you use? How much? Can you tell us all there is to know because your plants are gorgeous! And inquireing minds must know!
Hi RamPuppy,

Well thank you, flattery will get you everywhere!

I use Osmacote (Dutch manufacturer) 10:11:18 + 2 MgO, slow release (6 month type). It can either be mixed in with the media or just sprinkled on top. Most species absolutely love it. Some like it quite a lot, some are indifferent and some (a very few e.g. N. argentii in particular) don't seem to like it at all.

But (and this is a biiiiiig BUT) is that we water from above very heavily. This is essential to prevent buildup of salts around the roots which will burn the roots eventually if not washed away regularly. We only use this type of fertilizer since we have the right conditions for it and it works better that foliar feeding, probably because we water so much. The reason we water so copiously by the way, is to try to emulate natural conditions since it rains a lot in most Nepenthes natural habitats. Water flowing past the roots also washes away certain chemicals that the plant excrete through the roots.

I have read Jeff Schafer write words to the effect that these plants developed carnivory for a reason and that feeding the pitchers with prey is the best way of feeding Nepenthes. I agree 100% and would love to feed all my plants naturally, but we have so many it's just not practical to do that. I have tried all sorts of whacky things. At one time we had many baskets of rotting fruit hanging all around the nurseries to breed fruit flies. It worked, especially for small seedlings with tiny pitchers that caught lots of flies. Then the rats moved in. Yum! Fruit to eat and plants in pots that could be chewed up to make nests, thank you very much! On one night we lost over 300 plants. The next night on another bench, every single plant had been chewed off at the base. On moving the pots we found several things like this:


So, no more fruit or fruit flies after that!

Feed your plants crickets, or use dilute foliar feed (about 1/4 recommended strength) but beware of root feeding unless you can flush it through regularly.

By the way, does anyone know where the miconception that Nepenthes cannot absorb nutrients through the roots comes from? Most Nepenthes develop pitchers to catch prey as an adjunct to absorption of nutirents through the roots, not as a total replacement. Those species that grow in peat-swamp-forest have peat-tea to drink which contains a variety of chemicals. It may be that some species (e.g. those that grow on laterite soils) absorb trace elements from the soil that are not present in sufficient levels in insect prey. Iron for example? Or calcium perhaps? we've tried everything from egg-shell water to chelated iron preparations. Some things work on some species and not on others. I'm not at liberty to tell all at this stage.

In case anyone is still awake and has read this far, here's another photo. N. spectabilis x ventricosa - an easy grower.



UGH and I thought I had a problem with the occasional mouse making a home!

On the fertilizer issue:
I agree 1000% as well that the best way to feed your plants is with insects the natural way.  Personally I think that with the 'soil' mixes most people use and the pure water, many plants are being starved if they are not feed in some manner.  Yes Nepenthes have developed means to suppliment their nutrition but they are certainly not growing in nutrient free soil either and being watered with distilled water.

The important thing to remember here is that everyones situation is different with respect to how plants will respond.  Experimentation on each individuals part is the only answer.  But before you experiment and try nonnatural suppliments, be aware that you can kill your plants just as easily as give them a huge boost in health.  What might work to give great results for one person might be a death blow for another grower.  If in doubt and you can manage.. feed your plants the natural way with insects!  The results are just as impressive and less risky.  ok enough of that..

In my situation plants are watered every day during the summer to every 2 or 3 days during the winter.  I normally opt for liquid feeding in a drench.  I think it gives me better control and is easier.  Some risks however are leaf and pitcher burning.  I use a hydroponics type fertilizer that has all macro and minor elements and is low in urea.  

I have been fiddling around with some Osmocote after talking with Rob about it.  Partly because I am always trying new things looking for a better way to grow and produce healthy vigorous plants.  I am experimenting with Osmocote Azalea Camella Rhododendron formula.. Supposedly is more acidic with extra sulfur.  Not sure if this matters but the local Lowes didn't have much to choose from and I didn't want to buy 50lbs commercially for a few trials.  It has a 4 month release time at 70deg with a 9-6-6 formula.  I have not tried incorporating it into the potting media when planting.  I have sprinkled it on top of the soil as well as scratched it into the surface slightly.  So far on the few plants I have tried it the results are very promissing and better than the liquid feeding.  There is a down side for me as well.  In my situation it is causing algae growth on the surface of the potting medium.  This may or may not become a problem.  If you look close at the picture you will see some green areas

Why do I think the Osmocote is giving better results so far:
The Osmocote is there feeding the plants every day.  At this point I only fertilize with the liquid feed several times a month at most.  The plants however are growing every day!  I would like to run some trials with a fertilizer injector and see how that compares.. maybe next Spring.

Here is a picture of one plant I am using the Osmocote on after about 4 months of time.  The plant was also repotted from a 3.5 inch pot to a 3/4 gallon at the same time, which might attribute to some of the size increase.  Other plants repotted however without the Osmocote did not show such a drastic change.  All plants were also fertilized with my liquid feed whenever it was applied, including this one with the Osmocote.

Heh, I guess there is a change now! The old saying never fetilize Neps will be You can fertilize them only in very small quantity's. I am going to look forward into this for my own use.
Very interesting read guys... I may try it someday when I have a green house, but as things stand now, I don't, and profusely watering a terrarium only results in a much aquarium... so, hehh... it won't be happening anytime soon...though, I do have a couple of nepenthes that are potted out in my living room... home depot plant one of them... smells ripe for experimentation!

Thanks for the info...

question... what did you do with the pinkeys?
Good point on the terrarium thing. It would be very risky to use in an enclosed area where you could not regularly flush the pots and build up of minerals is a risk.

I bet the Macrophylla had first dibs on them.
I've been using osmocote for almost 2 months now, mostly because I know of a nursery around here that uses it on it's nep plants. At first I was a little skeptical, but it really is amazing how fast their plants grow! I bought a teeny tiny N xCoccinea from them around March, and by june it was 2 feet in diameter!

I sprinkle a few osmacote pellets on soil surface and then just let them be. It's been raining alot lately though, so I'm not worried about the roots burning. I can't say anything conclusive so far, but I'm of the opinion that it does help them grow faster. The newer leaves on some of the plants are much larger, and they are still producing pitchers. Algae is the big problem though, especially when the pellets are on LF sphagnum. :s I repotted a few plants though, and I put the pellets on top of the soil, and then the sphagnum on top of that, so maybe that'll prevent the algae from coming back.

One question though, Which neps would you say absolutely hate being fertilized? I'm thinking mostly of N northiana (haven't given any fertilizer to that plant)...

Could you give the plants fewer pellets, and be able to water it less often?
  • #10

I use about 8 pellets per 3" pot. Any fewer than this and there is a real risk of not giving the plants the correct ratio of nutrients. I'm informed that Osmacote pellets are not identical. Some contain the Nitrogen, some the Potassiuim and Some the Phosphorous. Others may contain the Magnesium Oxide and others the trace elements. This may well be so, since the pellets have slightly different colors Therefore, even using 8 pellets per pot, there's a little chance of my plants getting nutrieints in the ratio 10:11:18 + 2 MgO. All I can say is that it works for me.
  • #11
Great! I may try some osmocote on cuttings that I can spare or a rajah offshoot when the next batch of offshoots is ready to come off in a few months.

Wow Rob, I'll bet you jumped a bit when you saw those baby rats! I used fruitflies but only in a terrarium.

For you who grow in terrariums and want to do the pot flush and use fertilizers you can do it if you leave your plants in their pots and not bury them in soil. Then you can take them out and put them on a slotted shelf over a 5 gallon pail and water through the pot that way. I combine twice monthly Urea Free 30-20-20 liquid orchid fertilizer (I think It's Growmore brand but I can't remember offhand) + balanced liquid micronutrients and feeding crickets as well as 2-4 times weekly pot flushes with R/O water this way. I rarely use Superthrive because I don't notice a real increase in growth by using it. I do use it when making 1-2 node cuttings, but that may be more superstition than anything else...!
  • #12
my tank is really hard to get plants in and out of, as it is, I am worried that in a few months the only way to move some of them will be to chop them up for cuttings... it's a 1 piece acrylic tank, so it's got access 'ports' cut out on top, but I can't just reach in and move plants around...

though, I am getting ready to re-do my substrate, it's a year and a half old, and I want to re-fresh it...

guys I also want to caution the more inexperienced growers and new to growing people, fertilization CAN be done, but it is best I think to wait for a little experience, one wrong dosage and your neps will have burned roots... so exercise with caution.
  • #13
And burned roots equal what ladies and gentlemen? *everyone thinks* A dead or near death nepenthes!

Might I also add to Steve comments about fertilization, we are growing these plants in a virtually nutrient free media so every now and then with a shot of fertilizer would benifit them but exercise caution as always when fertilizing ANY plant. I personally don't fertilize but use plant enhancers myself.
  • #14
Rob, i just got this sample pack of Schultz multi cote 18-6-12 time release 9 months all purpose plant food in the mail today is this safe to use on the plants
  • #15

No fertilizer is necessarily safe! As others have warned, burned roots are a real risk and feeding the pitchers with suitable prey is probably best. Do be careful if you are experimenting with Osmacote and only use a little. I've only been able to tell you what works for me here in the tropics with twice daily watering. Many growers are using terrarium conditions and root feeding is probably dangerous since salt buid up and attacks by fungi and other pathogens are much more likely in stagnant conditions.

As to the type of Osmacote, (or Shultz multi-cote which I assume has similar release properties), we experimented with a lot of different compositions. All of them worked to a greater or lesser extent, but ones containing trace elements and particularly Magnesium (in the form of 2% MgO) worked best.

Do be careful and I strongly suggest you don't try it on any valuable plants. If you use it, sprinkle it on the top of the pot and water coiously from above every day. That way you can remove the pellets if things go wrong. Don't mix it in with the media, it doesn't yield any better results that way and any ill-effects are difficult to reverse.

Oh, and by the way, don't try putting any directly into pitchers. We did, the pitchers die. We documented the results quite thoroughly!

Good Luck!
  • #16
Rob, thanks for the info i just checked the packet and magnesium is at 1.00%. belive me i will not try it on any of my
valuable plants. i got a couple of hybrids i can try it out on. most of my plants are outside here in florida. with getting watered/ mist in the morning then mist once again at night. like you said i will only put it on the serface just in case i do have to pick it out.
  • #17
Hey Rob

Thanks for that fertilizer tip. I know how much experimentation it takes to get that sort of knowledge. When I was growing TC bananas in South Africa, Osmocote became too expensive to use, and it took me a whole growing season and lots of man hours to get new standards.

Do you guys ever use those polymers that expand when wet in your mixtures? We had a kind of fern which needed more water than the surounding plants, and ended up mixing some of that in with the fern mixture, and the problem was taken care of.

I was thinking it could be valuable for terreriums to lessen the frequency and thus cost of using distilled water on neps.


  • #18
well, yesturday i put 8 pellets on the soil mix of N. Judith Finn, N.Gracilis, & 4 on N. Truncata. cause it is the small one. well keep you up to date. watering will be once in the morning/misting & misting once again at night.