Nepenthes fertilizer

[kitkor]

Hey folks,

I recently donated a large Nepenthes Deroose alata (mostly alata with a little ventricosa, I think) to the greenhouse at the college I work at. Office politics, you know, have kept the person who has absolutely no botanical training and little interest in botany running the greenhouse. Needless to say, even with careful instruction and my constant attention, the plant has been abused. It hasn't produced pitchers in a couple months and the older leaves are yellowing at the edges. New leaves initially look fine, but it takes only about 3-4 weeks before they too begin to turn yellow. I water with RO water obtained from the lab I work in and temperatures/light are excellent in its location. The other Nepenthes I have at home don't have this problem.

While examining the sad leaves today, a visiting professor made the observation that yellowing older leaves can be an indication of nitrogen deficiency. Because of all the abuse, the plant hasn't produced pitchers and hasn't been fed in months. I've never had to supplement the soil with fertilizer before and was looking for advice. I've heard a dilute orchid fertilizer will work. Any experience with this?

So what do you think? Is nitrogen deficiency the likely culprit? What else causes early yellowing of the leaves? Will a dilute 20-10-20 orchid fertilizer do the trick? One application only?

Thanks in advance.

[unstuckintime]

Long time gone, i read of "Superthrive" being appropriate for Nepenthes, to be sprayed on the leaves. Which doesnt make any sense, but thats what i have read. Now, in my opinion, getting a very dilute (I'm talking only hundredths of a mole per liter, here) could do some good. My advice would be to top water it, and not to soak, on perhaps a every-other-watering method.

[dash3echo]

What's the humidity in the greenhouse? I would suspect that a malnourished plant would still produce pitchered leaves...they would just be smaller; stunted. If your plant is completely aborting the traps, i would look to humidity before nitrogen requirements.

[kitkor]

Jan 22, 2009 1:56:55 GMT dash3echo said:

What's the humidity in the greenhouse? I would suspect that a malnourished plant would still produce pitchered leaves...they would just be smaller; stunted. If your plant is completely aborting the traps, i would look to humidity before nitrogen requirements.

I can't give you a definite measurement as I don't think there's a hygrometer in the greenhouse, which has been neglected for some time. Recently humidity has been getting better with the installation of an automatic watering system the college bought two years ago, which does a good job at watering the floor, but even before that installation the humidity was decent.

Like I said, this plant has been abused. It was initially kept at the manager's insistence in her dry-as-a-bone office for three weeks to "check for infections" ... And then, it was moved to another dry-as-a-bone low-light office for "display" ... well, you get the idea. That was about 5 months ago, though. Since then it had been recovering in the greenhouse and began to produce small pitchers. But by the time they were almost fully developed, the maintenance department shut off the heat to fix some pipes on one of those subzero days. That pretty much killed off any pitcher development. Around the same time (before the deep freeze), I noticed the older leaves yellowing. Doubt it's the humidity - my Neps overwinter in my kitchen and don't produce pitchers due to the low humidity there, but their older leaves don't yellow.

unstuckintime, I've heard of foliar fertilizer as well. I've never used superthrive before, but I'll have to look into it. Thanks.

[sarracenialover]

i see what you mean when you said that the plant was abused. I would also suggest superthrive (although some ppl on this board advies against it, but its worth a try). I've used Superthrive on my cephs during transplanting. They have recovered well.

[dash3echo]

Yikes! Must be a bit of a slap in the face when you've worked so hard to maintain a healthy plant like that and it ends up going south because someone else didn't invest the time. Good luck with the recovery though...

[manders]

Humidity can be important, but also for ventrata / alatas they like a lot of light before they will pitcher, if it can get a few hours sunlight that should do the trick. Be carefull though if its been in shaded conditions for a long time that you don't burn the leaves. Small doses of a high nitrogen fertiliser will help, either diluted orchid fertiliser or sprinkle a small quantity of osmocote on the compost.

[chloroplast]

There are many things that can cause leaves to yellow or turn a lighter shade of green. In your case, it could be:

1. Good sun (not necessarily a problem if the plant has adapted). But you should also see some red color on the leaves if this is the problem.
2. Iron deficiency (and many other nutrient deficiencies, for that matter).
3. Infestation. Sice the topgrowth is otherwise fine, I suggest checking the root system for pests like mealybug.
4. Root disease. This might be the culprit given the plant was not watered well for weeks. Root disease causes the plant to be in a relative state of dehydration since transpiration is occuring faster than water uptake. This can cause discolored, smaller leaves to form and early death of the leaves.

I suggest unpotting your plant to check for infestation/root damage. If the roots look fine, you can put it in medium shade for a few weeks to see if the leaves become greener or add some 1/4 strength urea-free fertilizer to the pitchers or soil.

Ken

[taz6122]

I'm no pro but I would not add fertilizer to the soil. Mix your orchid fertilizer at 1/4 strength and using a Q-tip apply it to the underside of the leaves being careful not to soak the Q-tip where it will drip onto the soil. Two or three leaves should do. I use fish food to fertilize the pitchers but don't over do it. I apply one cichlid pellet per pitcher per week and my raff is doing great. It has seven functional pitchers with more on the way.

[kitkor]

Wow, there appear to be many disparate opinions out there regarding fertilizer. I assumed there would be and thank all of you for your input. I suppose it really depends on trial and error.

I do remain mostly convinced it is the nutrition, although I am intrigued by the micronutrient (iron) comment above. I did repot it about 2 months ago and the roots looked fine (repotting was necessary after I discovered the manager had used the wrong soil mixture, not a big deal, but I imagine if I hadn't specifically said peat moss the plant would have ended up with the peat humus that is in the potting room). It's now enjoying a 2:1:1 peat:sand:perlite mixture. The new leaves aren't stunted at all and grow to the regular size. It's just that the older leaves (by older I mean maybe three below the growth point) begin to go yellow at the edges, which is abnormal for past experience with this plant. Light is controlled by the greenhouse automated shade system, which gives it mostly a few hours a day of direct sunlight and filtered the rest. Doubt that's much of a problem.

The one thing most sources I've read agree upon is a dilute urea-free orchid fertilizer high in nitrogen and relatively low in phosphorous and potassium at one-quarter strength is fine. I've only seen occasional caution not to place the fertilizer on the soil.

Thanks again, all. Much appreciated! Wish me luck :-)

[SundeWCitY]

I really dont know what to say however for my input id say perhaps it hasnt caught enough prey and doesnt have sufficient nutrients, for my plants i got a local pet store and buy medium sized crickets and just throw the bag in the freezer , then when they r little ice cubes i use tweezers and put them in the pitchers, the plants really love it and I have noticed a large growth spurt from starting it on my truncata , I have always been to scared to try fertilizers , however i do try a few drops of superthrive in my spraybottle now and then , good luck perhaps this can help

[justjack]

Wow this is an old topic. Your not getting much response from the big guys because you can dig through the previous threads where this has been covered. Many CP books cover this as well. One short cut; sunbelleexotics.com/Sunbelle/Culture_Neps_GrowSecrets.htm

[philgreen]

Yep, your likely to get many opinions.
So here's my input.

With all the moving around it's had and then having been repoted only 2 months ago, it could have been just suffering a bit of stress and still settling in. It needs to be left un-messed around with for a while.

To my mind that soil mix sounds more like a Sarra compost than a Nep mix, I would think it's too compact and wet. Neps like an open mix that drain very freely and maybe even dries out slightly (not totally dry). I would add at least 2 parts bark to your mix and maybe even some LFS.

Most problems tend to be either wrong compost / temps / air too dry or too little light. Nutrition is unlikely to be the problem in so short a time, but adding a little is unlikely to cause any harm.

Hope it recovers.

[frilleon]

I would have to agree with philgreen on this one. I too also think this might have a lot to do with your soil mix. It does sound like Sar. type of mix leaning on the wet side. I use the mix for Neps right out of the Savage Garden. It works great for me! It even contains charcoal to help filter the water/soil in case there is some build up. For the most part it is a open soil. The deluxe recipe (which can be obtained right from his website) is one part each of long-fibered sphagnum, peat moss, perlite, pumice, lava rock, vermiculite, fine orchid bark, and charcoal.

[corners]

I bet the person watching it or someone else is probably watering it with tap water. Probably figure water is water to them