# Urea fertilizer - outstanding results



## polyantha (Aug 2, 2014)

It all began with the MSU fertilizer: Many of you guys have had good results with urea firtilizers. And I did not with my MSU that I tested for two years. The previous fertilizer from a local orchid nursery was much better actually. Root growth was ok, but no new growths and yellowish colour of the leaves.
So I was looking for a new fertilizer. I like eggshells plants and I asked him some months ago what he is using. Fertilizer with high urea. And Xavier also mentioned that urea fertilizers are great. And I know some german breeders who use urea fertilizers too with urea only as N source.
After some research and browsing through hundreds of fertilizers from cannabis over bonsai to citrus fertilizers i found Vertofol Royal. This is a lawn fertilizer 14+4+4 with urea only as N source.
Some months of testing and I finally got the results I wanted to see. New growths everywhere and a very nice dark green color. I was not sure if it was just pure imagination, so I made pictures of some plants I bought half a year ago from a nursery who uses a fertilizer without urea. So here you go. Believe it or not, this is not Photoshop!












And there are new growths everywhere:drool:

adductum:





philippinense:





gigantifolium:





sanderianum.





rothschildianum:





anitum:





ooii:





roth x gig





So if someone is not satisfied with his fertilizer: go for it and buy one with urea!

Poyantha


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## NYEric (Aug 2, 2014)

Personally, I switch up fertilizers fairly whimsically.


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## Justin (Aug 2, 2014)

i too have used urea fertilizer (Miracle Gro orchid food) for the past 12 months with my multifloral Paphs, and my results are exactly the same as in the pictures above. Nice green, strong growths and new starts showing up everywhere. 

Fertilizer is only one variable in culture but it is important.


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## gonewild (Aug 2, 2014)

Just curious why you think darker green is an indication of better growth?


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## Cheyenne (Aug 2, 2014)

gonewild said:


> Just curious why you think darker green is an indication of better growth?



Figured that was coming.


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## Ozpaph (Aug 2, 2014)

Looks like you are getting great results.


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## consettbay2003 (Aug 3, 2014)

I have found that using urea as a nitrogen source causes the ph of the media to drop considerably between waterings. With a ph of 6.5 for my 
fertilizing solution, the ph in the pot drops to approximately 4.8 5/6 days later.


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## Stone (Aug 3, 2014)

Outstanding result!
How are you suppling calcium? Dolomite?


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## Stone (Aug 3, 2014)

gonewild said:


> Just curious why you think darker green is an indication of better growth?



Really?


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## Paul (Aug 3, 2014)

nice dark leaves!! 
personnaly I use 50% 50% both nitrates and ammonium, and get very good results too. leaves are darker and bigger than previously (even when using urea fertilizer) and big roots.
But plants also get plenty of Calcium and Magnesium, and low K & P + kelp extract. 
Do you supplement your plants with other things?


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## polyantha (Aug 3, 2014)

gonewild said:


> Just curious why you think darker green is an indication of better growth?



More new growths are a sign for better growth. No one proved color as a criterion yet.


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## polyantha (Aug 3, 2014)

Stone said:


> Outstanding result!
> How are you suppling calcium? Dolomite?



I use limestone at the moment and it works fine. Especially my mexipediums like it.


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## polyantha (Aug 3, 2014)

Paul said:


> nice dark leaves!!
> personnaly I use 50% 50% both nitrates and ammonium, and get very good results too. leaves are darker and bigger than previously (even when using urea fertilizer) and big roots.
> But plants also get plenty of Calcium and Magnesium, and low K & P + kelp extract.
> Do you supplement your plants with other things?



No i just use fertilizer in combination with limestone. But I have a question: how do you supply magnesium? Epsom salt? Magnesium dolomite?


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## Brabantia (Aug 3, 2014)

Your experiments confirm what I have observed on Phalaenopsis. I use also for these a fertilyser with plenty of urea ( plant in pot from LIDLE). I use as recommended by Wang a potting made of peat moss and bark (Compo)... I never have such nice plants and flowers. Actually I test also for Paphs, in alternance with a like KLite, a home made fertilyser having 70% NNO3 and 30% NNH4+ ... It has a NPK ratio of 3/1/1. I use always a 40 ppm N concentration one time per week.


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## Clark (Aug 3, 2014)

Polyantha- I am curious about this lawn fertilizer, Vertofol Royal.

I have used several different brands on my lawn, and prefer Scott's.
One of the reasons, is the color of the leaves. Just perfect!
Scott's advertises that this is a result of iron.
I have used 2% iron. But this product rocks at 5% iron.
http://www.scotts.com/smg/catalog/p...rod10610005&itemId=cat50034&icid=hp1_mm_p_slf

Does Vertofol Royal contain iron?
Thank you.


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## Ray (Aug 3, 2014)

polyantha said:


> More new growths are a sign for better growth. No one proved color as a criterion yet.



Well, if that's "proof", then I have got to praise the K-Lite formula with no urea, as ALL of my paphs have become "puppy mills" over the last while. This is typical:






Not that I'm shooting down the concept that urea might have value - I know a couple of large-scale paph growers that swear that a tiny addition (one adds it to K-Lite) is a benefit.


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## polyantha (Aug 3, 2014)

Clark said:


> Polyantha- I am curious about this lawn fertilizer, Vertofol Royal.
> 
> I have used several different brands on my lawn, and prefer Scott's.
> One of the reasons, is the color of the leaves. Just perfect!
> ...



Vertofol Royal doesn't contain iron as far as I know. Perhaps that is the next step to take.


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## Clark (Aug 3, 2014)

I wouldn't change a thing if I was you.
Nice plants btw.


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## gonewild (Aug 3, 2014)

Stone said:


> Really?



It was a pretty simple question asked to the author of the thread who presented examples of the use of UREA. But if you want to answer, to be perfectly clear, let me re phase the question.....

Why do you think dark green leaves indicate better plant growth than lighter green color?


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## orcoholic (Aug 3, 2014)

I'd also like to get an answer as to why dark, green is better. 

The dark green paph looks like it isn't getting enough light. Maybe with urea added the amount of light can be increased?


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## tomkalina (Aug 3, 2014)

We actually alternate our fertilizers using K-Lite (nitrate based) one week, MiracleGro 30-10-10 (urea based) the next week and Wuxal Calcium ( nitrate + urea based) the third week. Then a flush with plain Chicago water (Lake Michigan) for it's micros the fourth week.

While the fertilizer formula varies from week to week, the TDS of the final fertilizer irrigant never exceeds 130 ppm while the monthly Chicago water flush runs about 220 ppm TDS. Probably more complicated than it needs to be, but it seems to be working.


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## Bob in Albany N.Y. (Aug 3, 2014)

Has anyone been using the miracle grow for tomatoes? I have been using a bag of that and then a bag of the regular miracle grow. That said I'm no expert it's just easy to buy this time of year and store up on it. I've been doing this for a few years now.


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## ALToronto (Aug 3, 2014)

Once again, this thread shows that there is no magic fertilizer that will solve everybody's problems. It's not just the fertilizer - it's a multi-factor interaction between source(s) of N, other fert ingredients, potting medium, source and quantity of Cal and Mag, water quality. And that's with having perfect culture conditions. 

Can we maybe do a chart? People who are having good results, please post what you grow and how you grow them. Type of pot, medium ingredients, humidity, temp, water, fertilizer data, Calcium and Magnesium source and quantity, anything else that you feel is relevant. I'd like to compile the results and maybe, just maybe, create some good combinations of growing conditions so that those of us who are treading water have some comprehensive guidance.

I'll try to come up with a spreadsheet tonight, and I'll put it in my public Dropbox folder. Then we can all contribute.


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## PaphMadMan (Aug 3, 2014)

Thanks for the laugh. Watching orchid growers debate fertilizer use can be quite entertaining when I'm in the mood.


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## Ozpaph (Aug 3, 2014)

Bob in Albany said:


> Has anyone been using the miracle grow for tomatoes? .



yes. Not sure if the formulation is the same, though. I use it < half strength and alternate with kelp.


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## Stone (Aug 3, 2014)

gonewild said:


> > Why do you think dark green leaves indicate better plant growth than lighter green color?
> 
> 
> 
> Darker green leaves in the same growing situation means higher chlorophyll content which means more photosynthates which means more food for the plant which means more growth.


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## NYEric (Aug 3, 2014)

I'm having a lot of good leaf growth in Paphs. I am also being better about watering and grooming for pests so...


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## gonewild (Aug 3, 2014)

Stone said:


> gonewild said:
> 
> 
> > Darker green leaves in the same growing situation means higher chlorophyll content which means more photosynthates which means more food for the plant which means more growth.
> ...


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## Stone (Aug 4, 2014)

gonewild said:


> Stone said:
> 
> 
> > > Seeing new growths starting is excellent but one or two new growths is normal and not a result of the type of nitrogen.
> ...


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## paphioboy (Aug 4, 2014)

Interesting.. No wonder they green up when I pee on my slippers  :evil:

The question of why dark green is better than light green is interesting. From my viewpoint, I like plants under my culture to look like wild plants (I think the foliage colour of wild plants are good indicators for optimum conditions). For most of the multiflora species that I am familiar with and of which I have seen photos of freshly-collected plants, the leaves are much darker than those in culture. I think this is likely a result of nutrition rather than just light.

If you look up one of the articles Xavier has written, he details the growing environment of one of the best paph growers in Malaysia (in Cameron Highlands) to be very shady (3 layers of shade netting), planted in fern root, only plain water, no fertiliser. Leaves are glossy black-green even for multiflorals and obviously such plants perform very well (said grower often takes home prizes for almost the whole paph category during competitions). 

Page 13 of this document: 

http://eurobodalla.org.au/fileadmin...012/Paphiopedilum_culture_and_propagation.pdf


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## NYEric (Aug 4, 2014)

paphioboy said:


> Interesting.. No wonder they green up when I pee on my slippers  :evil:



Good. I'm not the only one that thought that!


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## eggshells (Aug 4, 2014)

To be fair, K-lite users coin the same phrase that their plant has more "green or dark green" growths when they compare it to their previous fertilizer regime. Not that I disagree with that as most of the paphs in the wild that I have seen (not other genres) showcase dark green in colouration as paphioboy said. 

My point is why can't others who uses a different fertilizer use the same comparison (in this case green/darkgreen growths whatever) and now being questioned why they think the colouration of their plant showcase "healthy" while K-lite users uses the same phrase and for them it is an improvement? I see double standards there.

I'm not dismissing the benefits of k-lite as it seems like some if not most people are doing great with it but you can't dismiss others who uses other types of fertilizer and still works for them. I see lots of growers here in this forum and other that doesn't use k-lite and still showcase beautiful plants. 

FWIW Me and my friend had been using fertilizer with urea for years with no problems. See Paphman910's stonei thread. I'm pretty sure others here as well.

P.S. Both nicely grown plants (Both Polyantha and Ray's)












(not my photo)


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## gonewild (Aug 4, 2014)

eggshells said:


> To be fair, K-lite users coin the same phrase that their plant has more "green or dark green" growths when they compare it to their previous fertilizer regime. Not that I disagree with that as most of the paphs in the wild that I have seen (not other genres) showcase dark green in colouration as paphioboy said.
> 
> My point is why can't others who uses a different fertilizer use the same comparison (in this case green/darkgreen growths whatever) and now being questioned why they think the colouration of their plant showcase "healthy" while K-lite users uses the same phrase and for them it is an improvement? I see double standards there.



Fair? Double standards? 

I never mentioned k-lite or any other fertilizer in connection to my question about dark green color.

I talked about UREA and dark green color and gave a few reasons why some people should use UREA with caution.

I asked a question about why dark green is being used as a standard of perfection. Most if not all professional growers consider dark green as not growing at optimal rates. No argument that dark green leaves are beautiful. But the dark green shown in the first photo set is too dark, perhaps it is the camera settings but it is represented as accurate. However the closeup pics of new growth all have medium green color... not dark.

No double standards, use any term you like, be happy with your plants but this thread may mislead someone into making a mistake by switching to UREA which can be problematic for plant health. As well it sets an idea that dark green is a sign of perfect growth. Is it?

The pictures you showed of wild paphs are beautiful. Do you remember where you got them? They look somewhat like some pictures from an area of artificial replanted plants in a natural area. I'm not saying they are but would be nice to validate that they are naturally growing.

UREA gave positive results to Polyantha, my question is why? And why were MSU results so poor? I think these are interesting questions and pertinent to this thread

There is plenty of published info about UREA toxicity which is the same as ammonia toxicity and it can damage plant tissue under certain conditions especially when non soil media is used. 

Here is another question....
Can using UREA fertilizer at standard doses damage plant tissue?


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## gonewild (Aug 4, 2014)

Maybe I don't know what is considered as dark green foliage.
Here are two wild Paph pictures from orchidspecies.com

Are these leaves dark green?


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## gonewild (Aug 4, 2014)

Here is an easy to understand video about Ammonium (UREA) toxicity.

http://www.greenhousegrower.com/video/plant-culture/v-avoiding-ammonium-toxicity/
..


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## SlipperFan (Aug 4, 2014)

I'd call those a medium green. Of course, medium has a range of values. I've always heard that dark is like forest green, and indicates too little light. There is no absolute, except maybe whatever works!


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## Stone (Aug 4, 2014)

gonewild said:


> Maybe I don't know what is considered as dark green foliage.
> Here are two wild Paph pictures from orchidspecies.com
> 
> Are these leaves dark green?



Obviously if a plant such as the roth there is growing in full sunlight, its leaves can never be dark green no matter how much N it is getting. I have seen other pics of roth growing in shaded spots which were much darker.
However, the plant will grow wherever the seed lands. If in full sun, it will be destined to be yellow and more stunted than its counterparts. So there is an optimum position for all plants.
For the urbanianums?? above I would say that they are in the optimum situation. No doubt there are others nearby in a much sunnier place which don't look as good or as lush. BUT! have a look at how much light they are recieving! Still very bright. Easily as bright as my G/house yet they are what I would call the ''perfect'' colour for this type of Paph. Obviously exremely healthy and prolific. So you CAN have dark green leaves in very good (relatively) bright light and this points more to the nutrition they are getting.


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## Stone (Aug 4, 2014)

Ozpaph said:


> yes. Not sure if the formulation is the same, though. I use it < half strength and alternate with kelp.



I have used it but stopped because ther were too many preciptates forming. They should never put Cal nitrate together with the sulphates and Phosphates!!! (which they do!)
Always mix your Cal nitrate seperately then add it to the FINAL solution when completely diluted.

One of these days I'm going to manufacture and market a fertilizer which I actually like. :evil: But its gotta be a 2 part no question!


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## Bjorn (Aug 5, 2014)

I cannot resist:evil:
A couple of years back http://www.slippertalk.com/forum/showthread.php?t=22386 I wrote about my experiences spraying a PEOY With urea. Of course it greened up more or less instantaneously. and I found out that urea easily enters the plant tissue through the epidermis and can therefore by-pass the roots. That is why most foliar feeds are based on urea i recon.
Later, I used K-lite for a year or so, until I realised that the plants were getting sickly yellowish, even though the N-Level was arond 50ppm. Last year I started to mix K-lite with an urea based foliar feed (50:50) the pH was adjusted with citric acid, and things started slowly to green up. Finally, this year (February 2014), I changed to the urea based foliar feed with citric acid and with Ca-nitrate additions. Simultaneously I lowered the fertiliser level to <10ppm of N.
During this time, my plants did not become dark green which I attributed to my light levels.
The change came however once I started to spray my plants with mancozeb and copper in order to get rid of some notorious fungal problems. More or less immediately some plants responded with strong growth and darker foliage. Particularly a compot of randsii; these plants more or less doubled in size (within two months) and the plants turned from yellowish green to dark green. Not all species have responded like that but I have not seen negative effects either.
These observations have made me quite convinced that the micronutrient make up of common fertilisers are inadequate, both proportions (Fe:Zn:Mn:Cu) and quantity. And of course, ammonium-ions are positively chaged and will therefore not become leached easily, as does the negatively charged nitrate ion.


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## Paul (Aug 5, 2014)

Hello Bjorn,

Mancozeb provides high Zn, Mn and also Nitrogen. So very good for greening up plants that suffers deficiency. You will have the same (or probably better) result with kelp extract that is very high in all micronutrients
Paphs (especially multifloral) are known to need high Zn, Mn and Cu (search for Xavier works in the forum)


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## Bjorn (Aug 5, 2014)

Exactly Paul, so why are they making the fertilizers with almost reverse proportions Fe:Zn:Mn?
I have been using Kelp rather extensively but the effect came with the mancozeb. One disclaimer though, it may also come from copper, I add some copper-oxychloride to the mix. I do spray on dendrobiums as well, have not seen any negative effects on them but I use hard water for mixing the spray. For reference; Xaviers anecdotes particularly abour Vacherot et Lecoufle.


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## Brabantia (Aug 5, 2014)

Some reflections about this subject:
A plant with green leaves absorbs it more light than a plant having yellow leaves?
If a plant absorbs more light make it more sugars?
If yes it should make more dry material and have an accelerated growth versus a plant with yellow leaves.
If you can say yes at these questions and affirmations here are the reasons why one wants green leaves.
PS: Members of my club and myself have also observed that all nitrate fertilysers make plants with yellow leaves.


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## gonewild (Aug 5, 2014)

Stone said:


> Obviously if a plant such as the roth there is growing in full sunlight, its leaves can never be dark green no matter how much N it is getting. I have seen other pics of roth growing in shaded spots which were much darker.
> However, the plant will grow wherever the seed lands. If in full sun, it will be destined to be yellow and more stunted than its counterparts. So there is an optimum position for all plants.
> For the urbanianums?? above I would say that they are in the optimum situation. No doubt there are others nearby in a much sunnier place which don't look as good or as lush. BUT! have a look at how much light they are recieving! Still very bright. Easily as bright as my G/house yet they are what I would call the ''perfect'' colour for this type of Paph. Obviously exremely healthy and prolific. So you CAN have dark green leaves in very good (relatively) bright light and this points more to the nutrition they are getting.



It was a yes or no question! You wrote more than 150 words and still did not answer the question.


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## Ray (Aug 5, 2014)

To Bjorn's earlier comment: It's a matter of degree, but the foliar uptake of urea is far greater than that of ionic species, while just the opposite is true of the roots, where ionic species bond instantaneously with the roots so that they cannot be extracted by rain, while nonionic stuff like urea is easily extracted.

I also have to think that there was "something else" contributing to the yellowing of your plants with K-Lite, as that is the only fertilizer I have given my plants since November of 2011, and I'm seeing nothing of the sort.


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## gonewild (Aug 5, 2014)

Brabantia said:


> Some reflections about this subject:
> A plant with green leaves absorbs it more light than a plant having yellow leaves?
> 
> It probably absorbs less light since it is reflecting more of the green light. The dark leaves absorb more heat energy which may be a good or bad thing depending on the environment.
> ...


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## Brabantia (Aug 5, 2014)

gonewild said:


> Then the nitrate fertilizers are not being used correctly.


Do you think on a too high pH? 5.6 would be better that 6 when we use a fertilizer having the total of its nitrogen under nitrate form?
Thank you for your comments.


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## TyroneGenade (Aug 5, 2014)

Plants can up- or down-regulate chlorophyll levels in response to light. In dim light they will increase chlorophyll so they can harvest more light. In bright light they may decrease it or simply not make as much. There is only so much photosynthesis that can occur. This is limited by the amount of water, nitrogen, CO2 etc... Simply increasing chlorophyll does not directly translate into more photosynthesis and more growth. For instance, the yellowness of leaves of plants grown in strong light is because of an increase in carotenoids. These carotenoid molecules will absorb blue and green light and emit yellow light. They play another import role and that is as free radical scavenger. Blue light photons tend to damage chlorophyll and produce more free radicals so the plant has to adapt to this by becoming more yellow (if this doesn't happen fast enough then the leaves burn). The carotenoids can transfer some of the light energy to the photosystems that do the energy capturing steps of photosynthesis but this is small (estimates range between 4 and 40% with the better studies favoring the lower values). So, no, dark green leaves do not necessarily mean more photosynthesis and nor do light green leaves mean less photosynthesis. Leaf color is only evidence of leaf color.

Light green or yellow leaves have multiple sources. It can be due to a failure to produce chlorophyll as caused by a lack of Fe, Mg, B, Mo etc... AND nitrogen. The urea could, since it is absorbed via the leaves (thanks Lance, I never knew that) make up for a nitrogen deficiency caused by problems with the roots or medium.

There is lots of evidence in this thread that the urea made up for some deficiency in culture but no hard evidence that it is better than alternative fertilizers that are used under proper conditions. Perhaps, if you have a plant struggling and it hasn't got a good root system then maybe the urea fertilizer is the way to go? (At least, this the idea this thread gives me.)

It may be worthwhile noting that K-lite is a 12:1:1 (NPK) fertilizer and the urea based one discussed here is 14:1:1. MSU is 13:3:15. The urea fertilizer is much closer to being a version of K-lite than a "normal" fertilizer. If anything, it has less K than K-lite.


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## polyantha (Aug 5, 2014)

gonewild said:


> It was a yes or no question! You wrote more than 150 words and still did not answer the question.



"Are these leaves dark?" and posting some of the lightest green paph leaves on the net is not a yes-or-no question, it is a rehtorical question oke: That's why Stone didn't give you an answer I guess


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## gonewild (Aug 5, 2014)

polyantha said:


> "Are these leaves dark?" and posting some of the lightest green paph leaves on the net is not a yes-or-no question, it is a rehtorical question oke: That's why Stone didn't give you an answer I guess



I did not choose the lightest green paph leaves on the net. Because the discussion had focused on multifloral type paphs and the declaration was made that in nature they have dark green leaves I searched for pictures of them growing in situ. These are what came up, not many to many choose from. I have seen many pictures of them over the years and they are always medium green and not what I would call dark green. Stone says he has seen pictures but does not share them as examples.

SO I asked an honest question that relates to the paph species discussed. Based on that maybe we can understand what people perceive to be dark green.


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## gonewild (Aug 5, 2014)

TyroneGenade said:


> Plants can up- or down-regulate chlorophyll levels in response to light. In dim light they will increase chlorophyll so they can harvest more light. In bright light they may decrease it or simply not make as much. There is only so much photosynthesis that can occur. This is limited by the amount of water, nitrogen, CO2 etc... Simply increasing chlorophyll does not directly translate into more photosynthesis and more growth. For instance, the yellowness of leaves of plants grown in strong light is because of an increase in carotenoids. These carotenoid molecules will absorb blue and green light and emit yellow light. They play another import role and that is as free radical scavenger. Blue light photons tend to damage chlorophyll and produce more free radicals so the plant has to adapt to this by becoming more yellow (if this doesn't happen fast enough then the leaves burn). The carotenoids can transfer some of the light energy to the photosystems that do the energy capturing steps of photosynthesis but this is small (estimates range between 4 and 40% with the better studies favoring the lower values). So, no, dark green leaves do not necessarily mean more photosynthesis and nor do light green leaves mean less photosynthesis. Leaf color is only evidence of leaf color.
> 
> Light green or yellow leaves have multiple sources. It can be due to a failure to produce chlorophyll as caused by a lack of Fe, Mg, B, Mo etc... AND nitrogen. The urea could, since it is absorbed via the leaves (thanks Lance, I never knew that) make up for a nitrogen deficiency caused by problems with the roots or medium.
> 
> ...



Well said, thank you.


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## tomkalina (Aug 5, 2014)

Some great information here. I never realized urea based fertilizers were primarily useful as a folliar feed.


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## gonewild (Aug 5, 2014)

Brabantia said:


> Do you think on a too high pH? 5.6 would be better that 6 when we use a fertilizer having the total of its nitrogen under nitrate form?
> Thank you for your comments.



There really should not be much difference seen between pH 5.6 and pH6.

If you are using nitrate fertilizers at recommended doses and leaves are yellow and not green then something is far out of balance. pH is important but pH5.6 or 6 is good. So must be something else.

If the members of your club all have the same problem with nitrate fertilizer having only yellow leaves then look at what you all have in common. What forms of nitrate are you using? Are you sure you are using fertilizer with a high ratio of nitrate compared to ammonia? Are you all using the same nitrate source?

Before UREA is used by plant roots it is changed into nitrate in the soil so even when you apply UREA the plants are eating nitrate.


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## gonewild (Aug 5, 2014)

Concerning the comparison between nitrate and UREA...
I have been researching information on ammonia toxicity dealing with some fertilizer issues and came across this UREA use info. Since it relates directly to the point of this thread I'll share the link.

http://scienceinhydroponics.com/2010/05/urea-in-hydroponics-positive-or-negative.html

The info is about hydroponic use but in reality since most orchids are grown in soil less media hydroponics apply very closely.


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## Stone (Aug 5, 2014)

tomkalina said:


> .
> 
> 
> > I never realized urea based fertilizers were primarily useful as a folliar feed.[/
> ...


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## Stone (Aug 5, 2014)

Paul said:


> > Paphs (especially multifloral) are known to need high Zn, Mn and Cu (search for Xavier works in the forum)[/
> 
> 
> QUOTE]
> ...


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## Stone (Aug 5, 2014)

gonewild said:


> It was a yes or no question! You wrote more than 150 words and still did not answer the question.



If the question was ''are these yellow leaves'' then the simple answer (if you need one) is yes to the roth and no quite to the other one


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## Stone (Aug 5, 2014)

gonewild said:


> > Before UREA is used by plant roots it is changed into nitrate in the soil so even when you apply UREA the plants are eating nitrate.
> 
> 
> 
> Its first changed to ammonium (which is held on colloids) in a couple of days and SOME is changed to nitrate (which is easily leached) after that.


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## Stone (Aug 5, 2014)

gonewild said:


> ]
> 
> 
> 
> ...


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## gonewild (Aug 5, 2014)

Stone said:


> If the question was ''are these yellow leaves'' then the simple answer (if you need one) is yes to the roth and no quite to the other one



You fail. The question has nothing to do with "yellow".
The question was "Are these leaves dark green?"

Now I have to ask how you can say the roth leaves are yellow?

At least you are demonstrating my point (bet that hurts) 
You look at the roth and see yellow leaves and I see medium green.
I consider both plants to have medium green foliage. 
Both plants have leaf color that is natural for the plant growing in a balanced environment.


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## gonewild (Aug 5, 2014)

Stone said:


> gonewild said:
> 
> 
> > Its first changed to ammonium (which is held on colloids) in a couple of days and SOME is changed to nitrate (which is easily leached) after that.
> ...


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## gonewild (Aug 5, 2014)

Stone said:


> gonewild said:
> 
> 
> > ]
> ...


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## gonewild (Aug 5, 2014)

Here is an exert from a publication by Alabama A&M and Auburn Universities "Fertilizing Greenhouse Crops in Alabama"

"Normally, nitrifying bacteria in the soil convert ammonium and urea to nitrate, but the optimum pH for these bacteria is about 7.0. In soilless media where the pH is usually 6.0 and below, these bacteria may be less active. The bacteria are also much less active when the potting media is cool (less than 60 degrees F). In addition, high ammonium can contribute to stretching of plants under winter conditions. The availability of nitrate nitrogen to plant roots is not linked as strongly to media temperature or bacterial activity".

Pay attention to the last sentence... "The availability of nitrate nitrogen to plant roots is not linked as strongly to media temperature or
bacterial activity". In other words the benefit of UREA is sensitive to temperature and pH and so are the potential problems.


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## Ray (Aug 5, 2014)

> They aren't



...for terrestrial plants.


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## gonewild (Aug 5, 2014)

From Texas A&M....

Urea must first be converted to ammonia before it can be used by the plant. This conversion is dependent on the enzyme urease. Urease is another compound that is effected by factors such as temperature, moisture, etc.

Under cool temperatures urease is often rendered inactive and little, if any, N is available for plant growth.


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## gonewild (Aug 5, 2014)

From the university of Hawaii Extension Service.....

"Toxicity symptoms (nitrogen): Plants are stunted, deep
green in color, and secondary shoot development is poor.
High N causes vegetative bud formation instead of
reproductive bud formation.
Toxicity symptoms (ammonium): Roots turn brown and
appear unhealthy, with necrotic root tips; plant growth
is decreased; necrotic lesions occur on stems and leaves;
vascular browning often occurs in stems and roots; severe
chlorosis and stunting of new leaves are symptoms
on some plants.
Ammonium toxicity is common in soilless media,
in highly acidic media, and under low temperatures. High
carbohydrate and potassium levels in the plant can prevent
some of the toxicity symptoms in some plants.
Ammonium fertilizers tend to make the soil more acidic,
and nitrate fertilizers tend to make the soil more alkaline."


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## Stone (Aug 5, 2014)

gonewild said:


> You fail. The question has nothing to do with "yellow".
> 
> 
> > The question was "Are these leaves dark green?"
> ...


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## Stone (Aug 5, 2014)

gonewild said:


> Stone said:
> 
> 
> > > Did you read the link I gave? They tested hydroponically growing in organic media also.
> ...


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## Stone (Aug 5, 2014)

Ray said:


> ...for terrestrial plants.



They just aren't. All the orchid fertilizers here are based on Urea and have been for years.


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## Stone (Aug 5, 2014)

gonewild said:


> > Urea must first be converted to ammonia before it can be used by the plant.
> 
> 
> Wrong


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## Stone (Aug 5, 2014)

gonewild said:


> From the university of Hawaii Extension Service.....
> 
> "Toxicity symptoms (nitrogen): Plants are stunted, deep
> green in color, and secondary shoot development is poor.
> ...



All true and all irrelevent as I mentioned


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## gonewild (Aug 5, 2014)

Ummm one more.... this one is from Canada.


NH4+ toxicity in higher plants: a critical review

Based on this review it seems very risky to use UREA as the main nitrogen source when potassium levels are low.


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## Stone (Aug 5, 2014)

gonewild said:


> Ummm one more.... this one is from Canada.
> 
> 
> NH4+ toxicity in higher plants: a critical review
> ...



So give more K then


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## gonewild (Aug 5, 2014)

Stone said:


> So give more K then



No, wrong again, use nitrate nitrogen is the correct solution.

Mike, read the research data. You like to trust in published data, I'm providing published proof why UREA is not a good choice of nitrogen source for orchids.

Low K can aggravate the problem but giving more K does not solve the problem. I mention the potassium because as Tyrone pointed out the UREA based fertilizer discussed here is 14:1:1 (very low K). K-lite is formulated using nitrates to avoid the ammonia toxicity issue.


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## gonewild (Aug 5, 2014)

Problem solved, we can use the official leaf color chart. :evil:
From my perspective the middle green shades are the ideal leaf color. That is green with a shift toward yellow rather than toward blue. :rollhappy:


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## SlipperFan (Aug 5, 2014)

Interesting, Lance.


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## paphioland (Aug 5, 2014)

I'm sorry but this thread is hilarious.


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## Stone (Aug 5, 2014)

gonewild said:


> > No, wrong again,
> 
> 
> Waddayoumean wrong again:sob:
> ...


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## gonewild (Aug 5, 2014)

Stone said:


> Please not the K again... The fact is that orchid growers here have for decades used a fertilizer called Aquasol. Award winning plants.. K higher than N....N all Urea.




Wrong again! Aquasol has 60% lower K than N (NPK – 23: 3.95 : 14)
and all N is not from UREA. Get your facts straight. 



> There's no point arguing that it is not a good choice. It may not be the best but it works and works well if used with discrestion.



It may not be the best, use it with discretion? 
A warning the manufacture gives.... 
"DO NOT USE AT TEMP HIGHER THAN 30 degrees!" 
(They don't say why) 

That lets me out, I need to fertilize when temps are higher than 30. And what happens if I apply it when the temp is 28 and then it goes up to 34? Is that because the UREA might damage my plants roots?

Who's arguing? I provided published proof and you provide nothing... that's not an argument. Show some published proof that UREA is better than nitrates so we can have a valid discussion that benifits the ST forum. 

You say... "It may not be the best but it works and works well if used with discrestion".
I say.... why not look for a better solution and grow better plants without having to use discretion?


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## Stone (Aug 6, 2014)

gonewild said:


> > Wrong again! Aquasol has 60% lower K than N (NPK – 23: 3.95 : 14)
> > and all N is not from UREA. Get your facts straight.
> 
> 
> ...


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## Paul (Aug 6, 2014)

Thank you for the thread... lol
Now, I know what makes the big difference in my waterings: I always water at pH=7 (using ammonnitrate based fertilizer + rain water, or pure municipal water). So no toxicity at all, and every single plant is growing roots and leaves, even the small seedlings that were in the same pot for years with no evolution or plants considered as hard to grow (adductum, anitum, some albino forms...)


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## Brabantia (Aug 6, 2014)

gonewild said:


> If the members of your club all have the same problem with nitrate fertilizer having only yellow leaves then look at what you all have in common. What forms of nitrate are you using? Are you sure you are using fertilizer with a high ratio of nitrate compared to ammonia? Are you all using the same nitrate source?


All are using a copy of MSU (Akerne RainMix) made by a local nursery (Akerne - Antwerpen Belgium).
It is a full nitrate fertilyser. A few members have trumpeted that it does not work at all for the Masdevallias.


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## Carper (Aug 6, 2014)

Brabantia said:


> All are using a copy of MSU (Akerne RainMix) made by a local nursery (Akerne - Antwerpen Belgium).
> It is a full nitrate fertilyser. A few members have trumpeted that it does not work at all for the Masdevallias.



I've been using this for around 5 years now along with a good friend of mine in the UK. Since changing from the available products in the UK, both our plant collections have improved massively in every way, growth, blooms, roots etc. This has resulted in our awards as the plants have been entered at shows and judged. I mainly have a multifloral paph collection and my friend has a very large collection of masdevallia! He also has a few other species including vanda, dendrobium etc and they all get the same treatment. The results speak for themselves. I will admit that I do experiment and am always looking for ways to improve hence why I've also got k-lite and often use a workaround which involves adding calcium nitrate and magnesium sulphate to the Akerne with amended amounts. I have monitored and get varied results but I'm happy with what all 3 provide. My only concern was a slightly paler colour hence the possibility that I may incorporate another local feed at various amended dilutions at spontaneous intervals. This is our Miracle Gro water soluble lawn food @ 30.6.6. Link on further details are 

http://www.gardendirect.co.uk/garde...s-killers/miracle-gro-water-soluble-lawn-food

Gary
UK


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## gonewild (Aug 6, 2014)

Stone said:


> Man you really get excited Lance....Chill dude
> 
> Nothing you have ever written, posted or shown has benefited my orchid growing but I still read your posts for the fun. You put out question after question that leades nowhere. The published proof was provided by polyantha. Go back and see. In his case Urea was better than nitrate.



I'll pass on commenting on your personal insult all this does is drag down the quality of this forum.

If you can't reply with constructive informative input please refrain from commenting on my posts.

Polyantha did not publish "proof". At least not based on how you have defined proof in your previous posts.


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## Ozpaph (Aug 6, 2014)

Stone said:


> I have used it but stopped because ther were too many preciptates forming. They should never put Cal nitrate together with the sulphates and Phosphates!!! (which they do!)
> Always mix your Cal nitrate seperately then add it to the FINAL solution when completely diluted.
> 
> One of these days I'm going to manufacture and market a fertilizer which I actually like. :evil: But its gotta be a 2 part no question!



thanks for the insight.


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## gonewild (Aug 6, 2014)

Brabantia said:


> All are using a copy of MSU (Akerne RainMix) made by a local nursery (Akerne - Antwerpen Belgium).
> It is a full nitrate fertilyser. A few members have trumpeted that it does not work at all for the Masdevallias.



The problem is probably pH related.
Do you know the pH of your water and media?

Basically....
The type of nitrogen has more of a direct effect on the growing environment than on the plant itself. As plants absorb nitrate the media pH increases and as they absorb ammonia the pH decreases. So if your water and media pH is tending on the high side of the scale using pure nitrate nitrogen will move the pH higher to a point where the plants can't take up enough nutrients. Balance this by using both nitrates and ammonia nitrogen at the same time. 

Using pure ammonia nitrogen works the same in the opposite pH direction. UREA results as ammonia nitrogen. The major difference when using pure ammonia nitrogen and having the pH moved lower is that at low pH levels ammonia is toxic to plant tissue.

When nitrates cause the pH to rise and a problem is created the plant simply stops getting food and turns yellow and does not grow.
When ammonia causes the pH to lower and a problem is created the plant tissue can (is) be permanently damaged. That is why 100% UREA based nitrogen is not advised to be used constantly for orchids. 

Ever wonder why your plants roots rotted and the top looks fine?
Ammonia in the soil kills roots and Ammonia (UREA) as foliar feed keeps the foliage alive all at the same time! But that is a different subject.


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## Bjorn (Aug 6, 2014)

gonewild said:


> The problem is probably pH related.
> Do you know the pH of your water and media?
> 
> Basically....
> ...



I am of the opinion that soil and orchid potting mixes are not the same and that we therefore should be careful about transferring conclusions from soil to orchid potting mixes. 

Basically, if we look at the chemistry, urea in aqueous solution transforms to ammonia and carbon dioxide. Which itself could react to ammonium carbonate. There would be a surplus of ammonia though as each urea may react with one water to give two ammonia plus one carbon dioxide.

Depending on pH this ammonia gets converted to ammonium and this reaction is reversible. At high pH (around pH=8?) the ammonia gets to toxic levels. As such, the ammonia is increasing the pH by "stealing" acid(H+) from the substrate in the transformation to ammonium. Normally the pH of the substrate is low (5.5?) and acid enough to take care of any ammonia that is liberated..

If the ammonia gets too plentiful, free ammonia will skyrocket pH and become toxic. This is normally not the situation since the ammonia is liberated slowly and the urea addition is not that large. Well, perhaps some of the feedings at 250ppm N could have that potential....

What happens to the ammonium that is produced from the ammonia (while acid is consumed)? 
Some is going into the velamen and is absorbed by the plant while some acid is given off by the plant, and some gets adsorbed on negative sites on colloids and other charged surfaces. This ammonium may then become oxidised to nitrate which is either flushed out or taken up by the plant that will liberate an OH group per nitrate consumed.
Looking discretely at the processes in the root-zone will give the impression that ammonium gives lower pH while nitrate increases pH but it is not that simple as I have tried to explain above (ammonia eats acid while converting to ammonium). 
Additional to the charge transfer in connection to the uptake by the root, other processes run in parallell liberating or consuming acid. If you take the gross reaction of the decomposition of urea, disregarding loss of either ammonia or carbon dioxide, the pH should increase because of the transformation of ammonia to ammonium, but decrease again if the ammonium gets consumed by the plant.

just my twopence:sob:


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## gonewild (Aug 6, 2014)

Bjorn said:


> I am of the opinion that soil and orchid potting mixes are not the same and that we therefore should be careful about transferring conclusions from soil to orchid potting mixes.



Agree. Take notice that I refer to "soil less media" in order to clarify conclusions. Also I want to point out that most of the info that I posted links to declare that soil less media is more sensitive the the ammonia than soil.



> Normally the pH of the substrate is low (5.5?) and acid enough to take care of any ammonia that is liberated..



Let's define normally. Growing in bark heavy media the pH will be as you say (5.5?).
What about non bark media heavy in leca, diatomite, limestone, perilite, pumice, carbon, CHC, ect? Some Leca media comes as pH9!
What about the effect liquid fertilizer has when applied directly to areal roots?

I think maybe there is no normal orchid media and that is what makes it hard to have a standard pre made fertilizer formula that works for everyone. But if the pH is considered maybe that becomes the standard point to find what "normal" is to base the nutrient decision on.



> Additional to the charge transfer in connection to the uptake by the root, other processes run in parallell liberating or consuming acid. If you take the gross reaction of the decomposition of urea, disregarding loss of either ammonia or carbon dioxide, the pH should increase because of the transformation of ammonia to ammonium, but decrease again if the ammonium gets consumed by the plant.



In some of the published material I linked it stated that the pH swing can be extreme and happen very fast as much a 2 pH point change in a short time as the UREA is converted. If the root zone pH is near a safe point of say 6.0 pH could move to 4.0 or 8.0. But if the pH is already on a border line it could move toxic in either direction, although I think the rapid move is downward. The lower pH area is where ammonia toxicity is of most concern.



> just my twopence:sob:



Good info thank you.
How do you relate this with using UREA as the sole nitrogen source in fertilizer for a hobbyist orchid grower?


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## TyroneGenade (Aug 6, 2014)

A question: can we order our experiences by supplying the following information:
1. Fertilizer(s) used
2. Potting medium
3. Medium pH (if measured)
4. Response by plants

As the potting medium is critical to the issue knowing what it is could help. It is also worth remembering that adding lots of N to the medium will have knock-on effects on the availability of other nutrients:






This is not the type of discussion with a simply answer.


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## NYEric (Aug 6, 2014)

Actually, when I saw the 4 plants originally posted "without Urea/With urea" I thought the first (top left) one was getting too much light and the last (bottom right) one was not getting enough light.


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## orcoholic (Aug 6, 2014)

NYEric said:


> Actually, when I saw the 4 plants originally posted "without Urea/With urea" I thought the first (top left) one was getting too much light and the last (bottom right) one was not getting enough light.



Me too. I also thought the one not getting urea was much better looking. The one getting the urea did not look healthy at all.

I'd love to see if anyone has bloomed a plant with the leaf color that looks like the one that got the urea.


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## gonewild (Aug 6, 2014)

TyroneGenade said:


> This is not the type of discussion with a simply answer.



This looks like a map through a laser security system! 
Looks like Calcium is the Boss.


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## AdamD (Aug 6, 2014)

Calcium must be an evil villain, look at how antagonistic it is!


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## gonewild (Aug 6, 2014)

AdamD said:


> Calcium must be an evil villain, look at how antagonistic it is!



And Nitrogen, the Hero does not have many friends. Only way N can get to Ca is through Cu. N needs more green.


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## polyantha (Aug 6, 2014)

I don't want to change the subject, but are there special formulations to get good root growth? Because that is the only thing that was better on previous fertilizers and since my plants have many new growths now, I could focus on the roots the next months.


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## gonewild (Aug 6, 2014)

polyantha said:


> I don't want to change the subject, but are there special formulations to get good root growth? Because that is the only thing that was better on previous fertilizers and since my plants have many new growths now, I could focus on the roots the next months.



Is there something wrong with the roots now? 
How have they changed?
How do they need to be improved?


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## Stone (Aug 6, 2014)

polyantha said:


> I don't want to change the subject, but are there special formulations to get good root growth? Because that is the only thing that was better on previous fertilizers and since my plants have many new growths now, I could focus on the roots the next months.



There is no question that better roots are made with nitrate and root growth is depressed with ammonium but top growth is increased (this is according to experiments with various grasses) So unless it can be proved by trials that a certain plant grows better in every way using one or the other, use a 50/50 mix to get more balanced (and often increased) top and root growth. Here, growth of Phalies was enhanced with nitrate ratios up to 75% to 25% ammonium. afterwhich growth started to be reduced. All nitrate is no good as is all ammonium/urea. When I say no good, I mean ''not as good'' as it could be.
http://hortsci.ashspublications.org/content/43/2/350.full


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## paphioboy (Aug 7, 2014)

Ok. Back to the point of paphs in-situ having dark green leaves... 

Not all roths grow in such exposed situations as in the photo posted earlier. A more typical leaf colouration of roth in-situ:
http://m0.i.pbase.com/o2/48/839548/1/142283210.uJDqYx7w.Paphiopedi_hEnroe.jpg

Hennisianum in-situ
http://farm3.static.flickr.com/2813/12063441145_fcb0e91939.jpg
http://farm8.staticflickr.com/7310/12064340736_38db65ef9e.jpg

Henryanum in-situ
https://www.orchidsforum.com/attach...canh_9152012_201291573035851675949-jpg.23081/

Several other barbata species in-situ which I have posted in an earlier thread:
http://www.slippertalk.com/forum/showthread.php?t=28510&highlight=hookerae


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## paphioboy (Aug 7, 2014)

A good link for stonei in-situ
http://sarawaklens.blogspot.com/2009/11/paphiopedilum-stonei-species-under.html

And obviously this humungous specimen
http://www.wildborneo.com.my/images/cld1204502.jpg

And these are photos from the collection of the best paph grower in Malaysia mentioned in Xavier's article. You can gauge how shady it is.. 

http://2.bp.blogspot.com/-5-pX_1PHWhw/TjcFBpbs7II/AAAAAAAAAHQ/A86RwAxeudU/s1600/DSC00078.jpg

http://4.bp.blogspot.com/-QNB0laWVN1I/TjcFLdCFK0I/AAAAAAAAAHU/k3c0hYrWiDY/s1600/DSC00079.jpg

A single lowii specimen
http://1.bp.blogspot.com/-qQ8v4WsdMzs/TjcEqZvC_OI/AAAAAAAAAHE/AlRcArlnCto/s1600/DSC00071.jpg

Plant of said lowii
http://1.bp.blogspot.com/-CtaKmSVKy90/TjcE5ZJVQgI/AAAAAAAAAHM/sm_IL21g4e8/s1600/DSC00077.jpg


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## paphioboy (Aug 7, 2014)

Wild-collected sangii (posted by Xavier in another thread). He has posted photos of collected plants in numerous threads but they are scattered..
http://img402.imageshack.us/img402/6103/sangii.jpg

More in-situ photos. Even brachys can grow quite shady in the wild
http://www.slippertalk.com/forum/showthread.php?t=32544&page=2

http://www.slippertalk.com/forum/showthread.php?t=32544&page=3

So this brings us back to the question: Is darker green better than lighter green?


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## Stone (Aug 7, 2014)

paphioboy said:


> So this brings us back to the question: Is darker green better than lighter green?



Thanks for posting these wonderful pics PB! The roth at the top is the same colour as mine. Yey.

I think the answer to your question is probably yes. At least for the barbarta types. Looks like Paphs can grow in very bright light but they always seem to have a yellowish tinge which is to be expected. But the shaded ones look more vigorous and prolific.

After another look at the hennisianums they don't seem to be growing in very gloomy conditions but I think I would struggle to achieve that colour whatever I did even putting them in deep shade, so something is still missing in our culture!
So can someone tell me what that something is?


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## polyantha (Aug 7, 2014)

gonewild said:


> Is there something wrong with the roots now?
> How have they changed?
> How do they need to be improved?



There is nothing wrong, if you mean wrong like "lots of dead roots". They are just not growing new root rips so easily. I didn' repot since using urea, but I did yesterday to be able to describe root growth with urea. So as a conclusion I can say it is good for vegetative growth, but not for root growth.
I used to get very vigorous fleshy roots when I gave very little fertilizer, but now root growth slowed down. This definitely must be because of the urea fertilizer, because I didn't repot in this time.
Overall growth has to be improved: At best there are lots of new roots filling the pot.


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## gonewild (Aug 7, 2014)

paphioboy said:


> So this brings us back to the question: Is darker green better than lighter green?



Great pics thanks for the effort to list them. 
The pictures show the exact reason I ask the question about whether the pictures I linked were dark green. Light green, medium green, dark green are all subjective.

My perspective is that most of the leaves in the links you listed have medium green foliage. I'm not talking about the dark green part of mottled leaves. i am talking the overall color of the leaf based on what it looks like. 
If you look at a leaf and ask yourself can this leaf be a lot darker aand you think "yes" then ask yourself can it get a lot lighter and still be green and you answer yest.... the the leaf is a medium green.

Leaf color changes with the mood of the plant a lot like skin color on a human. A doctor can look at the shade of your skin and see symptoms... and a horticulturist can do the same with leaf color.

If we assume a healthy normal leaf is medium green then we have a base reference point to use as a comparison. If the leaf color has shifted one way or the other we know what cultural conditions may need to be corrected. 

I see the healthy wild plants in your pictures as medium green and I adjust my evaluation depending on the leaf type. Certainly mottled leaf paphs have parts of their leaves very dark, but also have very light parts as well, so you have to look at the overall shade compared to a norm.

If your plants have been growing very pale and you change something and they get darker green you may think " they are a nice dark green now" when in fact they have only changed to medium green. This subjective color evaluation makes it difficult to diagnose a culture problem when someone says my plants have dark leaves. 

In the original pictures Polyantha posted that she described as nice dark green I see one plant as being dark green and the other as being medium green. Neither do I consider as "nice dark green". Both show nutrient or environmental issues than can be improved on. The dark plant is too dark and the other medium green leaves are not uniform in color and appear blotchy.


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## gonewild (Aug 7, 2014)

polyantha said:


> There is nothing wrong, if you mean wrong like "lots of dead roots". They are just not growing new root rips so easily. I didn' repot since using urea, but I did yesterday to be able to describe root growth with urea. So as a conclusion I can say it is good for vegetative growth, but not for root growth.
> I used to get very vigorous fleshy roots when I gave very little fertilizer, but now root growth slowed down. This definitely must be because of the urea fertilizer, because I didn't repot in this time.
> Overall growth has to be improved: At best there are lots of new roots filling the pot.



Did you take pictures of the roots?

This is why I was asking questions and not making conclusions until we know your facts. I know from past personal use that when UREA is used as a main nitrogen source at first overall growth looks quickly improved. That's because we can see the leaf color change. But we can't see the roots slow down. 

I'll comment more later.


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## polyantha (Aug 7, 2014)

gonewild said:


> The dark plant is too dark and the other medium green leaves are not uniform in color and appear blotchy.



Praestans has to be dark if you ask me. Nothing special actually, there are other praestans in my collection and they are among the darkest of my plants. Even without urea.


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## Ozpaph (Aug 7, 2014)

Thanks for the great photos but its almost impossible to tell how bright it is without some reference - the camera exposes to mid-gray.
Also that's the tropics when light intensity is strong and near vertical for most of the year, unlike most of us below the tropics.


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## gonewild (Aug 7, 2014)

polyantha said:


> There is nothing wrong, if you mean wrong like "lots of dead roots". They are just not growing new root rips so easily. I didn' repot since using urea, but I did yesterday to be able to describe root growth with urea. So as a conclusion I can say it is good for vegetative growth, but not for root growth.
> I used to get very vigorous fleshy roots when I gave very little fertilizer, but now root growth slowed down. This definitely must be because of the urea fertilizer, because I didn't repot in this time.
> Overall growth has to be improved: At best there are lots of new roots filling the pot.



Do the current roots all have active growing tips after this time under UREA nitrogen?


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## gonewild (Aug 7, 2014)

Ozpaph said:


> Thanks for the great photos but its almost impossible to tell how bright it is without some reference - the camera exposes to mid-gray.
> Also that's the tropics when light intensity is strong and near vertical for most of the year, unlike most of us below the tropics.



Also every camera brand produces a different shade of green. It's not just in the digital process it is in the glass of the lens. If you do a side by side comparison between top quality Canon and Nikon lenses you will see each one renders colors differently. So you are correct trying to compare foliage color over the internet is not very accurate at all. And yes tropical sun is very different. When I look at wild orchids I always look at leaf color and I rarely see one with what I would call dark green leaves. Granted I am not in Asia looking at paphs but I bet it is not much different there.


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## gonewild (Aug 7, 2014)

polyantha said:


> I don't want to change the subject, but are there special formulations to get good root growth? Because that is the only thing that was better on previous fertilizers and since my plants have many new growths now, I could focus on the roots the next months.



The option is to find the correct balanced fertilizer for your growing conditions. It's not really possible to focus on improving a selected part of the plants anatomy. Doing so will alter the rest of the plant. 

Since you feel that your nitrate fertilizer was not growing your plant tops well but did grow your roots well and now see the reverse with UREA you should realize that there is something out of balance.
It could be as simple as using a combo of both nitrate and ammonia but that may not be the route to the best growth.

The ideal thing is first to figure out why the nitrates failed, because they should grow a beautiful plant.
The only way to figure it out is to evaluate all your conditions involving water and media.
Do you know the pH of your water and media?
Do you know the buffer capacity of your water?
How much nitrate did you apply, ppm and frequency?
what is in your media?
What temperature are your plants in?
Does the media get really hot or cold?

Questions like these will lead to a solution.


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## gonewild (Aug 7, 2014)

When someone gives you a quick answer about a plant nutrient problem by looking at a photo without asking questions don't believe it. They have no idea what the illness is yet they prescribe a treatment, would you expect that from your human doctor? Plants are not mechanical machines or electronics that have a limited number of things that can break. plants are complex living creatures that are subject to an infinite number of possible maladys.


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## cnycharles (Aug 7, 2014)

Question was stated about root growth, and was pointed out that when weak fertilizer was used, lots of fleshy roots grew but seemed to stop after starting urea. Could be simple: little fert, plant goes looking and makes roots. At this time, urea is used and plant has tons of fert and decides it needs no more roots and just sits soaking up fert

Simplistic answers, and could be many others as well


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## gonewild (Aug 7, 2014)

cnycharles said:


> Question was stated about root growth, and was pointed out that when weak fertilizer was used, lots of fleshy roots grew but seemed to stop after starting urea. Could be simple: little fert, plant goes looking and makes roots. At this time, urea is used and plant has tons of fert and decides it needs no more roots and just sits soaking up fert
> 
> Simplistic answers, and could be many others as well



Could be as simple as that! (If the plant is lazy)
Will that still apply if the UREA was also applied in weak amounts?
I assume the UREA was applied at the same dose as the nitrate.


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## cnycharles (Aug 7, 2014)

Never know how hormone levels affect root growth based on nutrient types and levels, we all know that for many plants you overwater and they produce few roots; mete out water during growth and many plants produce more roots and longer to satisfy need. Possible correlation to feed types or quantity and growth/lack of


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## NYEric (Aug 7, 2014)

Scary! This thread has a life of its own!


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## Stone (Aug 8, 2014)

A possible reason that many people complain of ''not....yellow....but....not....so....green'' leaves with nitrate feeding is that they may simply not take it up or use it as effeciently as ammonium.
Many plants from acid evnvironments (where most orchids come from) prefer ammonium to nitrate.
Here is an example:http://www.ncbi.nlm.nih.gov/pmc/articles/PMC2802997/
Yet another case for including Urea/ammonium for at least some of the N
There are reasons for not using either exclusively


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## gonewild (Aug 8, 2014)

Stone said:


> A possible reason that many people complain of ''not....yellow....but....not....so....green'' leaves with nitrate feeding is that they may simply not take it up or use it as effeciently as ammonium.
> Many plants from acid evnvironments (where most orchids come from) prefer ammonium to nitrate.
> Here is an example:http://www.ncbi.nlm.nih.gov/pmc/articles/PMC2802997/
> Yet another case for including Urea/ammonium for at least some of the N
> There are reasons for not using either exclusively



Do you have any info of what type of nitrogen is leached in throughfall that you have referenced as the main nutrient source for wild orchids?

The Tea research is interesting.Some thoughts... I wonder how much it applies to orchids since Tea is extremely acid dependent like azelias and basically won't grow without a strong acid soil? Most orchid species come from environments with soil water closer to pH neutral. In this tea trial they do the experiment hydroponic so solid media factor is removed from the interface of plant to nutrient.


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## orcoholic (Aug 8, 2014)

polyantha said:


> I don't want to change the subject, but are there special formulations to get good root growth? Because that is the only thing that was better on previous fertilizers and since my plants have many new growths now, I could focus on the roots the next months.



I'm not aware of any fertilizers that concentrate on root growth. However, repotting and not watering too much should help encourage good root growth.

IMO you need to give the roots a "reason" to grow. Giving too much water and fertilizer keeps the roots from having to grow because everything the plant needs is right there. Watering less frequently makes the roots grow because they need to go deeper, or get longer, to get more water to support the upper growth.


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## SlipperFan (Aug 8, 2014)

I like that thinking!


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## Stone (Aug 8, 2014)

gonewild said:


> > Do you have any info of what type of nitrogen is leached in throughfall that you have referenced as the main nutrient source for wild orchids?
> 
> 
> 
> ...


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## Stone (Aug 9, 2014)

These are the first pics of emersonii in habitat I have seen!
http://www.bloggang.com/viewblog.php?id=taurus&group=3&page=2


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## orcoholic (Aug 9, 2014)

Polyantha,

Using the smallest pots possible will also encourage root growth.


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## paphioboy (Aug 10, 2014)

orcoholic said:


> Polyantha,
> 
> Using the smallest pots possible will also encourage root growth.



I think the reason is that the media dries faster and more aeration. However, to get paphs to grow vigorously, I think the root growth must not be limited. They should be free to roam, as Xavier has stated previously in his articles.


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## Rick (Aug 10, 2014)

paphioboy said:


> I think the reason is that the media dries faster and more aeration. However, to get paphs to grow vigorously, I think the root growth must not be limited. They should be free to roam, as Xavier has stated previously in his articles.



And certainly in the past with higher feeding rates, small pots drain much faster and retain much less NPK in the mix.

In general the situation with a small crowded pot is closer to the mounted condition with very short contact times from feed water.


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## paphioboy (Aug 11, 2014)

Another reason for what I said is that the roots of wild barbata-section paphs (examples which I have seen are barbatum, callosum, dayanum, javanicum) are often quite large, with many long roots that grow horizontally, rather than the measly root systems often associated with plants in culture..


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## ALToronto (Aug 17, 2014)

So why do we not mount paphs? Or has someone tried?


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## Rick (Aug 17, 2014)

ALToronto said:


> So why do we not mount paphs? Or has someone tried?



The basket method is kind of an intermediate version that I've had good results with. I've only heard of a single (henryanum) that was truly mounted and it did good.

Technically SH in inert media is a form of mounting and Ray has good results with that.

I think all the cliff dwellers and epiphytic paphs would do just fine mounted.


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## eggshells (Aug 17, 2014)

I'm experimenting on it. Just to see if possible if they can be mounted under culture. Though I don't see why not, It's presenting some challenges. The biggest challenge is humidity and watering. Perhaps if you have timed misters and air movement. It will be possible.

I'm just experimenting on the miniature ones.


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## Rick (Aug 17, 2014)

eggshells said:


> I'm experimenting on it. Just to see if possible if they can be mounted under culture. Though I don't see why not, It's presenting some challenges. The biggest challenge is humidity and watering. Perhaps if you have timed misters and air movement. It will be possible.
> 
> I'm just experimenting on the miniature ones.



What I tend to see when I open up a basket is roots clinging very well to the wooden frame, but not very well to all the limestone rock. Even though the roots are fully entwined through the rock, the rock is easily removed from the roots.

So I suspect that for a surface mounted paph you may need a very rough surface with lots of cracks and holes to wedge into.


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## Stone (Aug 18, 2014)

ALToronto said:


> So why do we not mount paphs? Or has someone tried?



I tried it and it's not worth the trouble. Too hard to keep them wet enough


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## Rick (Aug 18, 2014)

Stone said:


> I tried it and it's not worth the trouble. Too hard to keep them wet enough



Kind of funny since we go through such extreme gyrations (repotting frequency, pot configurations, potting mix recipes out the ying/yang......) to keep them from getting TOO wet and causing root rot.

Goldilocks syndrome :sob:


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## Bjorn (Aug 19, 2014)

Anyone bother to check the natural conditions? some of these things are growing more or less soaked. I remember some Pictures of voloteanum e.g.


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## Ray (Aug 19, 2014)

Bjorn said:


> Anyone bother to check the natural conditions? some of these things are growing more or less soaked. I remember some Pictures of voloteanum e.g.


I agree that "checking" the natural conditions is good, but it is only the starting point.

The vast majority of us absolutely cannot match the natural conditions of a plant, but through choices of media, pots, and watering schedule, we can still find a way to provide what the plants need.


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## gonewild (Aug 19, 2014)

Ray said:


> I agree that "checking" the natural conditions is good, but it is only the starting point.
> 
> The vast majority of us absolutely cannot match the natural conditions of a plant, but through choices of media, pots, and watering schedule, we can still find a way to provide what the plants need.



Natural conditions can never be replicated in a small space. Besides most people like plants to look better than they do growing in Nature so we have to learn how to change the natural conditions to get the desired results.
Paphs may grow naturally on "living" trees or rocks but when they do their roots are free to grow much more efficiently (straighter and longer) than when in a pot or mounted on a small piece of dead wood or stone. Roots need to be spread out and spaced apart or they loose their efficiency.


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## Stone (Nov 17, 2015)

Hi polyantha,

Have you continued with your urea feeding? If so are you getting good root growth as well?


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## Brabantia (Nov 17, 2015)

I am also curious to know what is occurred with these urea tests. 
Recently I read that ammonium (urea) supports the leaves growth and that the nitrates support the roots growth.


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## troy (Nov 17, 2015)

I beleive this is a pretty good base fertilizer, any input on this?


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## Justin (Nov 18, 2015)

I use Urea based 30-10-10 with tapwater and get excellent results including great root growth. I use kelp extract once per month too.


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## consettbay2003 (Nov 18, 2015)

Justin said:


> I use Urea based 30-10-10 with tapwater and get excellent results including great root growth. I use kelp extract once per month too.



I would be interested in knowing how many total ppm are in your fertigation solution. Do you supplement with Ca and Mg. ?


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## gego (Nov 18, 2015)

I would be interested to your media too.
Thanks


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## Justin (Nov 18, 2015)

According to my water report my tapwater has hardness of 100 ppm so there is already plenty of Calcium and Magnesium in it. It is low sodium (16 ppm) and has some nitrates (1.3 ppm). 

when I measure the TDS of my water it is usually around 150. pH out of the tap is about 7.5 and the runoff out of the pot is 6.5.

I use Miracle Gro orchid food which is 30-10-10 and includes Magnesium. I don't add extra Calcium.

I use about 1/8 tsp per gallon of water with every watering (much less for Phrags). If i need to green up my roths under strong lights i use a little more. (I grow indoors under lights).

i grow in a fir bark mix with charcoal and perlite, but this year i am going to switch everything to Orchiata and see if that lasts longer (will also provide more Calcium). I water everything twice a week so I think pushing plants with as much water as possible is really important. 

And as i mentioned i also use kelp once per month. 

I used to use Calcium Nitrate and K-Lite but I switched to Urea and never went back.


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## gego (Nov 18, 2015)

Thanks.

I'm curious because I am experimenting this actually because although nitrate is good for my vandas, most of my paphs are not happy.

I think the ph has to be low enough for a better uptake of the micros first then the macros. And urea will do that. I'm using RO so I'm adding CalMag supplement.
How long have you been using this?
I hope the OP will get us some update,,,,,
Thanks


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## Justin (Nov 18, 2015)

i switched from Calcium Nitrate to Urea about 2 years ago.


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## troy (Nov 18, 2015)

Urea base fertilizers will say urea base? I found a fertilizer the picture I posted on this thread, it has urea in it, would you reccomend it?


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## consettbay2003 (Nov 19, 2015)

I think it is important to remember that while a fertigation solution with a TDS of 150 appears a bit low the urea does not register on a TDS meter. The increase from the TDS reading of 100 for the tap water is increased by the potassium, phosphorus and other elements in the 30-10-10 fertilizer.
The urea is adding 49 ppm of nitrogen.


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## Justin (Nov 19, 2015)

The 150 TDS is what i measure out of the tap so the solution with fertilizer is probably 200 +. I am just going off of memory... The battery in my TDS pen is dead so I can't confirm.


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## gego (Nov 19, 2015)

Agree, urea doesn't show, it's not salt. Also the ph is neutral. So it could be that the solution starts at neutral ph then goes negative as the urea is broken down, ph goes up and down depending on what nutrient is taken up by the plant. This is just my double E thinking here so don't get excited. 

So we are only talking about nitrogen here, what about the uptake of the other nutrients, do they also affect the ph on the roots? The other macros are bases, so when they are absorbed is there an exchange of charges also?

Not very good in chemistry but I can understand charges pretty well. I hope the chemistry gurus in the forum will respond.


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## gonewild (Nov 19, 2015)

gego said:


> So we are only talking about nitrogen here, what about the uptake of the other nutrients, do they also affect the ph on the roots?



Yes, most nutrients are affected by pH. Some more so than nitrogen.


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## gego (Nov 19, 2015)

I mean when the other nutrients are absorbed thru the roots, is there any exchange of charges like the nitrogen uptake? And how?

So if potassium is taken up by the plant, does the process make the ph of the roots more acidic or basic? Or nothing.

Thanks Lance


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## gonewild (Nov 19, 2015)

gego said:


> I mean when the other nutrients are absorbed thru the roots, is there any exchange of charges like the nitrogen uptake? And how?
> 
> So if potassium is taken up by the plant, does the process make the ph of the roots more acidic or basic? Or nothing.
> 
> Thanks Lance



Yes there is.
Read this to get the basics....
http://www.ctahr.hawaii.edu/mauisoil/c_relationship.aspx


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## gego (Nov 19, 2015)

This is great!!!! Thanks alot.


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## polyantha (Dec 5, 2015)

Stone said:


> Hi polyantha,
> 
> Have you continued with your urea feeding? If so are you getting good root growth as well?



Hi stone, from the time I noticed the leaf color was good and the new growths were starting to grow I switched to another (standard) fertilizer because it is better for the roots. The Idea was to get those growths to a good size very fast. And they did. The new starter growths of P. gigantifolium you see at the first page of the post are now almost mature with leafs as long as 45cm /18in. It is a big plant now that has doubled its size within a year. I am looking forward to seeing a spike this winter.


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## Happypaphy7 (May 15, 2016)

How about this? oke:

http://link.springer.com/article/10.1007%2Fs11104-008-9852-5

I used to use Miracle Grow brand fertilizer with a lot of urea in it. I've also used other stuff like Tomato fertilizers.
I honestly never saw any differences at all.
Things all grew just fine for me.


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## paphioland (May 15, 2016)

Happypaphy7 said:


> How about this? oke:
> 
> http://link.springer.com/article/10.1007%2Fs11104-008-9852-5
> 
> ...




You don't even need an article to see this.


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## Ozpaph (May 16, 2016)

Happypaphy7 said:


> How about this? oke:
> 
> http://link.springer.com/article/10.1007%2Fs11104-008-9852-5
> 
> ...



good article - thanks


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## Stone (May 16, 2016)

I used this quite a lot over summer. Mainly Urea.
Very good!
http://www.bunnings.com.au/manutec-600g-orchid-food_p2961293


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## eds (Mar 11, 2019)

Sorry to drag up an old thread but it seemed better than starting a new one.

I'm wondering if anyone is still using urea based fertilisers and still getting good results? Or anyone who stopped using it due to bad results?

From reading various threads I'm wondering if alternating fertiliser types at low concentrations might give the best of all worlds? I've bought some of this to try, https://www.amazon.co.uk/Envii-Seaf...d=1552120741&sr=8-25&keywords=urea+fertiliser which says it has NPK ratio of 19:0:1.5 which seems promising and extra urea and iron as well as being made from seaweed. I'm thinking of alternating this with a rain mix / CaCO3 mix to supply nitrate and urea and whether it will be of benefit.


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## Justin (Mar 11, 2019)

I am still using 30-10-10. Less than 1/4 tsp per gallon of tapwater frequently. My Paphs love it.


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## troy (Mar 11, 2019)

I use a urea 16 16 16 acid base at 1/4 w ro alternated with 15-5-15 jacks cal mag at 1/4 w ro and my plants all have nice roots and grow well


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## eds (Mar 12, 2019)

Thanks guys will give it a go at my next watering. I figure mixing things up should give them a range of different N sources and mitigate any potential issues with each one.


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## Ray (Mar 12, 2019)

If you look at absorption mechanisms, I think it's interesting that while all three nitrogen species can be taken up by both roots and leaves, nitrate and ammoniums are preferentially absorbed by roots, while urea is via the foliar route.


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## tomkalina (Mar 12, 2019)

Using 15-5-15 w cal-mag during the winter months w lower gh temps, and 20-20-20 alternating w 30-10-10 during warmer months. Also using 1 tsp/gal Epsom Salts monthly from Mar-Sept. Pretty simple regimen actually.


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## eds (Mar 12, 2019)

Ray said:


> If you look at absorption mechanisms, I think it's interesting that while all three nitrogen species can be taken up by both roots and leaves, nitrate and ammoniums are preferentially absorbed by roots, while urea is via the foliar route.



So should we be dosing urea only foliarly (if that's a word!)? It seems some people are having success with it applied to the media/roots. (Perhaps as it's being converted to ammonia then nitrate.)


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## tomkalina (Mar 12, 2019)

Temperature in the growing area has a lot to do with the fertilizer formula we choose. In winter, when our gh temps can get below 60F at night, fertilizers containing more nitrate N than urea are used. In late spring and summer, we switch to a fertilizer that's more urea based because the conversion of urea to the more easily useable nitrate is temperature dependent. The higher the temp, the quicker the conversion.


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## eds (Mar 12, 2019)

So Tom can I ask why are you using urea based ferts if you think they're converted to nitrate before the orchid assimilates them? What do you think is the advantage to using urea?


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## tomkalina (Mar 12, 2019)

We use urea in summer because we've found nitrate based fertilizers are more apt to cause premature leaf loss when combined with high gh temperatures.


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## eds (Mar 13, 2019)

Thanks Tom. I was wondering if there was a cultivation reason or whether it might have been something as simple as cost!


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