K-Lite has been around a few years now... updates?

[Stone]

pH 4.0 is very close to being considered a food preservative acidic level and lethal to most microbes so I doubt most orchids would flourish at that level

I would not use that pH either. I'm just saying what he reported as the pH of the water coming off the branch where the Odonts grew.

pH becomes more important as the availability of nutrients falls. In organic media, Fe for example becomes almost unavailable to the plant unless there is a constant supply coming in. If there are adequate nutrients in the media water at all times pH is far less important. At a low pH (say 5.5) there will still be Fe available to the plant for an extended period of time even if none is supplied. Same goes for Cu and Zn and Mn to a lesser extent.'
Very generally though, I would say pH 7 is too low for acid loving orchids but probably good for your kovachiis and niveums?

 

[gonewild]

Very generally though, I would say pH 7 is too low for acid loving orchids but probably good for your kovachiis and niveums?

Do you mean to high?

 

[gonewild]

I would not use that pH either. I'm just saying what he reported as the pH of the water coming off the branch where the Odonts grew.

pH becomes more important as the availability of nutrients falls. In organic media, Fe for example becomes almost unavailable to the plant unless there is a constant supply coming in. If there are adequate nutrients in the media water at all times pH is far less important. At a low pH (say 5.5) there will still be Fe available to the plant for an extended period of time even if none is supplied. Same goes for Cu and Zn and Mn to a lesser extent.'
Very generally though, I would say pH 7 is too low for acid loving orchids but probably good for your kovachiis and niveums?

Mike, I know you don't like my unique theorys i suggest. But here's another one anyway. Just keep an open mind. (please don't ask me to show published research)

In the case of paphs/phrags that grow in or on limestone substrate...
The media pH is high and we tend to assume that we need potting media and water to be on the high pH alkaline side. BUT in nature the high pH limestone lies mainly below the roots. While the surface is covered in moss which we know has a lower pH acidic value. So perhaps the plants in Nature actually get acidic water with nutrients and not alkaline. I said in the past that I had very good results by adding chips of limestone to the substrate for kovachii as opposed to top dressing the media. I still used acidic nutrient water.
If anything I just said is fact then it would support the theory that the velum of the orchid roots take in the nutrients from free flowing water and the media becomes less important as a nutrient supply... But the pH of the media remains important. I'm not saying this is fact but that it may be a possibility.

 

[Stone]

Mike, I know you don't like my unique theorys i suggest. But here's another one anyway. Just keep an open mind. (please don't ask me to show published research)

In the case of paphs/phrags that grow in or on limestone substrate...
The media pH is high and we tend to assume that we need potting media and water to be on the high pH alkaline side. BUT in nature the high pH limestone lies mainly below the roots. While the surface is covered in moss which we know has a lower pH acidic value. So perhaps the plants in Nature actually get acidic water with nutrients and not alkaline. I said in the past that I had very good results by adding chips of limestone to the substrate for kovachii as opposed to top dressing the media. I still used acidic nutrient water.
If anything I just said is fact then it would support the theory that the velum of the orchid roots take in the nutrients from free flowing water and the media becomes less important as a nutrient supply... But the pH of the media remains important. I'm not saying this is fact but that it may be a possibility.

Oh I agree with that. I've mentioned a couple of times here a trial with alkaline growing ferns (Asplenium ceterach and A scolopendrium) where they found growth was equally good at pH 5.5 and 7 as long as the Ca was AT LEAST 4 times the Mg.
In this study, growth was good at 7.5 even when the Ca/Mg ratio was 0.33 (not very high!)
But the same ratio at pH 5.5 there was a Ca deficiency and more than half of the ferns where dead.
On the other hand, at a Ca/mg ratio of 4 (Ca four times the Mg) growth was excellent at both pH 5.5 and pH 7.5

 

[ChrisFL]

Falling from the sky where the air is absolutely clear of pollution it is pH 7.0.
As it drips off of moss in the Peruvian cloud forest pH is 7.0.

This is absolutely incorrect, as atmospheric CO2 dissolves into rainwater instantaneously and makes rainwater slightly acidic.

 

[ChrisFL]

The notion of neutral stem flow also strains credulity (I'm a paleoclimatologist that works on tropical hydroclimate).

 

[gonewild]

This is absolutely incorrect, as atmospheric CO2 dissolves into rainwater instantaneously and makes rainwater slightly acidic.

So you are calling me a liar? :fight:

It's what my meter displayed. Granted it is a cheap meter and may read slightly acidic as 7.0 but that's the reading.

 

[gonewild]

The notion of neutral stem flow also strains credulity (I'm a paleoclimatologist that works on tropical hydroclimate).

Geez........... I know how to take samples and read a meter.
(I'm a nobody that knows nothing I guess.)
:sob:
Rather hostile around now.

 

[Stone]

Do you mean to high?

Yes

 

[gonewild]

Yes

OK I will be on your side for a while.

 

[Bjorn]

Lots of interesting ideas. I see that the rhizosphere has been mentioned, we all know that plants detach adsorbed nutrients by liberating acid (mostly carbonic as far as I have understood, but even citric acid), but do we know that this also happens with orchids? Generally speaking, the orchids are devoid of hair-roots and even if paphiopedilum-roots are furry, I would not expect them to be very efficient as "nutrient collectors".

We know that the velamen has some unique properties with respect to nutrient adsorbtion and even paphs have a velamen......
Based on this, in my mind I have severe difficulties in accepting that nutrients that are adsorbed on/in the aggregates of the compost will be available to the plant unless there is a direct contact between roots and the adsorbtion site. This makes the nutrients in solution even more important. That is of course where the pH enters the scene, the solubility of different nutrients are dependent on the pH. But not only, there are a lot of chemical compounds that complexes with the nutrients and keep them in solution even at pH that is not favourable. Some potent and commonly found are citric acid and humates/fulvic acid. And then, there are those other synthetic complexants like EDTA that might- or might not - complex to such a degrree that the nutrients (normally Fe and Mn) get inacessible to the plants.

I have said this before and will repeat it here, most orchids are in nature found in locations that are devoid of nutrients. In order to grow and live in these environments, the plants have had to develop strategies making them able to make use of even very low amounts of nutrients.
If one or another nutrient (micro) is missing, then addition of more fertiliser helps - up to a point. But most of that increase in nutrient supply is wasted.
It is not straight forward to tell what nutrients are the limiting, but if one studies the local geology of the regions where the paphs are found, some indications can be found. E.g. for many of the islands of the indonesian archipelago, the soil is ultramafic with sometimes large amounts orf iron and manganese. Sometimes even nickel. For paphs from this region it is not unlikely that they can tolerate or even demand higher levels of these elements than does plants originating elsewhere.

Just my 2c

 

[gonewild]

Lots of interesting ideas. I see that the rhizosphere has been mentioned, we all know that plants detach adsorbed nutrients by liberating acid (mostly carbonic as far as I have understood, but even citric acid), but do we know that this also happens with orchids? Generally speaking, the orchids are devoid of hair-roots and even if paphiopedilum-roots are furry, I would not expect them to be very efficient as "nutrient collectors".

Exactly. Add also the fact that a high percent of the orchid root system is not in direct contact with substrate/media that might be holding bound nutrients. Orchid roots that are attached tyo a tree limb have maybe only 1/3 of their surface in contact with a solid surface while the other 2/3 are surrounded by open space. The open space is where flowing water will hit the roots. Orchids are highly evolved plants and it makes no sense that their roots would evolve to be only 30% effective at nutrient sourcing.

We know that the velamen has some unique properties with respect to nutrient adsorbtion and even paphs have a velamen......
Based on this, in my mind I have severe difficulties in accepting that nutrients that are adsorbed on/in the aggregates of the compost will be available to the plant unless there is a direct contact between roots and the adsorbtion site. This makes the nutrients in solution even more important. That is of course where the pH enters the scene, the solubility of different nutrients are dependent on the pH. But not only, there are a lot of chemical compounds that complexes with the nutrients and keep them in solution even at pH that is not favourable. Some potent and commonly found are citric acid and humates/fulvic acid. And then, there are those other synthetic complexants like EDTA that might- or might not - complex to such a degrree that the nutrients (normally Fe and Mn) get inacessible to the plants.

Also there is no reason to assume that the pH must be constant. In Nature pH fluctuates often. Ph of moist substrate may be very acidic or basic and then along comes the rain and brings a more neutral pH water flow. In the majority of orchid habitats there are nightly waterflows.

I have said this before and will repeat it here, most orchids are in nature found in locations that are devoid of nutrients. In order to grow and live in these environments, the plants have had to develop strategies making them able to make use of even very low amounts of nutrients.
If one or another nutrient (micro) is missing, then addition of more fertiliser helps - up to a point. But most of that increase in nutrient supply is wasted.
It is not straight forward to tell what nutrients are the limiting, but if one studies the local geology of the regions where the paphs are found, some indications can be found. E.g. for many of the islands of the indonesian archipelago, the soil is ultramafic with sometimes large amounts orf iron and manganese. Sometimes even nickel. For paphs from this region it is not unlikely that they can tolerate or even demand higher levels of these elements than does plants originating elsewhere.

There is also an assumption that orchid roots have evolved to function like other roots in absorbing nutrients in the from salts. The orchid habitats are low in nutrients in the elemental salt form. Not many nitrates flowing around in water or stuck to organic matter. That's where living organisms as a nutrient supply enter the real picture. The lichens , mosses, bacterias all produce complex excretions that the orchid roots have evolved to collect and process into nutrients for the plants. Our salt based fertilizers are simply a substitute nutrient supply that the orchids can survive on in the absence of the complex compounds from bio organisms (amino acids?).
I'll use that as an possible reason why one grower has great results using brand X fertilizer and another grower has less good or poor results. The good results are because the first grower's environment is supporting better micro fauna. And absolutely pH dictates what microbes can colonize the root system.

Just my 2c

I'm not thinking my idea is going to get a 2c value here.

 

[Ray]

I have said this before and will repeat it here, most orchids are in nature found in locations that are devoid of nutrients. In order to grow and live in these environments, the plants have had to develop strategies making them able to make use of even very low amounts of nutrients.

If one or another nutrient (micro) is missing, then addition of more fertiliser helps - up to a point. But most of that increase in nutrient supply is wasted.
It is not straight forward to tell what nutrients are the limiting, but if one studies the local geology of the regions where the paphs are found, some indications can be found. E.g. for many of the islands of the indonesian archipelago, the soil is ultramafic with sometimes large amounts orf iron and manganese. Sometimes even nickel. For paphs from this region it is not unlikely that they can tolerate or even demand higher levels of these elements than does plants originating elsewhere.

Thank you Bjorn. Those are two paragraphs I can agree with....

This may seem rude to some participants, so I'll apologize in advance...

All of these comments are great theories, but that's all they are, as none of us really has much of an idea of what is actually going on when it comes to orchids nutrition.

The mere fact that some have success doing what others fail with suggests that "plant nutrition" is more than just "fertilizer formula".

 

[tomkalina]

There's much more to growing than plant nutrition. You can have a theoretically perfect fertilizer formula but unless you can provide the correct amount of light, good water quality, suitable temperatures, good air movement, good humidity, suitable mix, etc., while controlling diseases and insects - the least controlled variables will limited your plant's ability to thrive.

 

[TyroneGenade]

That's where living organisms as a nutrient supply enter the real picture. The lichens , mosses, bacterias all produce complex excretions that the orchid roots have evolved to collect and process into nutrients for the plants. Our salt based fertilizers are simply a substitute nutrient supply that the orchids can survive on in the absence of the complex compounds from bio organisms (amino acids?).

Interestingly, one of the Catts I got last year was really struggling. Its roots had rotted, new growths were not getting anywhere and it looked like the end was drawing nigh... I'm a big believer in moss so I got a clump of live moss (regular garden variety) from outside and wrapped it around the base of the plant and stuck it back into S/H with the K-lite. It didn't take long for new growths and roots to emerge. I now have 3 lead growths on this plant and the growths look to be growing larger than their predecessors.

So far, S/H and K-lite is working well for my 3 experimental Catts.

I don't think there is anything wrong with the fertilizer in general, only that some plants might want a little more or less under different conditions. My problems might have more to do with the S/H than the fertilizer.

I'm going to keep using the K-lite.

 

[papheteer]

At what strength do you feed at and do you mix with the Kelp?

Gary
UK

never more than 1/8 tsp per gallon of water. I use kelp with fulvic and humic acids.

 

[Stone]

Generally speaking, the orchids are devoid of hair-roots and even if paphiopedilum-roots are furry, I would not expect them to be very efficient as "nutrient collectors".

Bjorn, I think the hairs on paph roots are exactly where nutrients are taken up (at least some) And on the contrary, they are supremely efficient at nutrient uptake. That is why an orchid can survive with just 2 live roots where any other plant would die.

We know that the velamen has some unique properties with respect to nutrient adsorbtion and even paphs have a velamen......
Based on this, in my mind I have severe difficulties in accepting that nutrients that are adsorbed on/in the aggregates of the compost will be available to the plant unless there is a direct contact between roots and the adsorbtion site.

I'm not sure what you mean here. Obviously if the roots (of any plant) are not in contact with a substrate particle it is impossible for the root to take up anything from that particular site. (Unless water liberates the nutrient and carries it to the root - which happens constantly)

This makes the nutrients in solution even more important.

Confused. More important than what?

 

[Stone]

Not many nitrates flowing around in water or stuck to organic matter. That's where living organisms as a nutrient supply enter the real picture. The lichens , mosses, bacterias all produce complex excretions that the orchid roots have evolved to collect and process into nutrients for the plants.

And where do think the mosses and lichens nutrients come from?

Here are the figures for the stem flow from trees with bryophytes (mosses and lichens together with everything in them like fungi, insects and bacteria) and without. (removed) in Yunnan.

With: (kg/ha)

Total N 0.84; nitrate-N 0.15; ammonium-N 0.54; P 0.04; K 1.44; Ca 0.57; Mg 0.46; Na 0.06; S 0.10

Without:

Total N 0.73; nitrate-N 0.29; ammonium-N 0.58; P 0.04; K 3.73; Ca 1.25; Mg 0.48; Na 0.07; S 0.13

So as you can see, the orchids are getting pretty much the same mineral composition from the stem flow as the bryophytes. In fact (apart from N) more without the bryophytes. BTW, notice how much potassium is in circulation compared to the nitrogen.

The good results are because the first grower's environment is supporting better micro fauna.

Considering the above, it would seem this is untrue.

 

[Stone]

All of these comments are great theories, but that's all they are, as none of us really has much of an idea of what is actually going on when it comes to orchids nutrition.

Many of the comments are theories. But the fact that a particular orchid does better (in every way) with heavier feeding is not one of them

The mere fact that some have success doing what others fail with suggests that "plant nutrition" is more than just "fertilizer formula".

Plant nutrition is no more than just a fertilizer formula. What else can it possibly be. That we don't all agree on what that formula should be does not change that.
The fact that some succeed where others fail using the same ''formula'', actually suggests that a factor OTHER than nutrition is involved.
More often than not it is simply the environment we supply and our skill at ''reading'' the plants that make the difference.

 

[gonewild]

And where do think the mosses and lichens nutrients come from?

The atmosphere.

Here are the figures for the stem flow from trees with bryophytes (mosses and lichens together with everything in them like fungi, insects and bacteria) and without. (removed) in Yunnan.

It's a really big stretch (exaggeration) to think you can remove all the micro organisms and then measure the stem flow to make this comparison. Besides stemflow is not where I said the nutrients come from. The microbes are in close or direct contact with the orchid plant in my scenario. Lichen growing on an orchid secrets nutrient compounds other than salts. small amounts of moisture transport the compounds to the plant roots. In some cases the microbes or lichens are directly on or in the orchid roots.

With: (kg/ha)

Total N 0.84; nitrate-N 0.15; ammonium-N 0.54; P 0.04; K 1.44; Ca 0.57; Mg 0.46; Na 0.06; S 0.10

Without:

Total N 0.73; nitrate-N 0.29; ammonium-N 0.58; P 0.04; K 3.73; Ca 1.25; Mg 0.48; Na 0.07; S 0.13

How can you relate stemflow on a per hectare level?
This equates to 0.084 grams per square meter of nitrogen that is not enough nitrogen to grow a forest, so this is BS.
But if you insist.... The stemflow with the bryophytes contains 13% more nitrogen than without. I wont mention that the bryophytes also remove over half of the potassium thus protecting the orchids from it's evil powers.

So as you can see, the orchids are getting pretty much the same mineral composition from the stem flow as the bryophytes. In fact (apart from N) more without the bryophytes. BTW, notice how much potassium is in circulation compared to the nitrogen.

There is no mineral flow amount at sufficient levels to feed the orchids in what you show above. This indicates the nutrients come from something other than stemflow and the nutrients are not in a form that the research has looked for. None of the published research has looked in the right place yet because science has made the assumption that orchid roots function the same and absorb the same nutrient sources as does a corn plant. Need to look at other compounds and not salts for the natural nutrient source. Seaweed extract works because it supplies other compounds.

Considering the above, it would seem this is untrue.

Not to me.