Purple leaves: Cold damage, Insect stress, too much light, magnesium or phosphorous

[thefish1337]

I think a component of the discussion that is being missed is the microbial populations in different people's orchids. Specifically the phosphate and potassium solubilizing bacteria associated with their orchids- if you lack theses functions in the microbial populations that live in and on your orchid roots then you are forced to overcompensate with increased additions of these nutrients.

Applying phosphorous as a salt and without appropriate microbial helpers means that your plant really only takes up phosphorous when it is in its ionic form in solution... the massive increase in concentration that occurs as evaporation and dry down cycles happen causes the phosphorous to be complexed with cationic species which become much harder for your orchid to take up. In a natural system there is a balance between phosphorous immobilization and mineralization/solubilization that dictates the availability of ionic phosphorous. Increasing phosphorous fertilizer without the appropriate microbiology just drives your orchid and media towards immobilization. Additionally, the organic forms of phosphorous that are contained in micro life are an important source of phosphorous as these organisms growth and death releases these organic forms which are less likely to form insoluble complexes. In systems with low organic matter (like most orchid mixes) the deleterious effects of excess salts on microbial populations are much more pronounced. If you combine this with the over use of synthetic pesticides which are harmful to nutrient cycling organisms and it becomes no surprise to me that people start compensating with higher feed rates. There is nothing wrong with this... other than you lose a lot of resilience and efficiency in your growing system.

You can meticulously balance nutrient ratios, or you can use microbes and be lazy but that's just my $0.02. I'd rather use less salts and preserve and promote the functional organisms I've inoculated into my orchids.

[Ray]

I am in complete agreement that microbes play a much larger role in plant health that we may realize.

To Keith’s question, I think that, for me, it’s not “what did I see” with their use on orchids, but more “what I didn’t see” - diseases of any kind. Tomatoes, herbs and figs grown in-ground were significantly bigger and more fruitful than their untreated counterparts, but that may be more related to general growth rate than the type of plant, per se.

A word about the reported contents of the probiotics. When it comes to “plant and soil amendments”, the category these products are registered under, the label does not have to reflect the full contents. It does have to show the species for which the manufacturer tests and guarantees the concentration. I cannot speak for others, but both Quantum-Total and Inocucor Garden Solution carry far more species than is reported on their labels.

For example, the Inocucor label states that it contains Bacillus subtilis and Saccharomyces cerevisiae, but the paperwork accompanying the shipment when I used to import it states the feedstock contains many others, and the PhD microbiologists that invented the product have told me there are a lot more species than they even know about.

[K-Sci]

Originally Posted by Ray

I am in complete agreement that microbes play a much larger role in plant health that we may realize.

Hmm. I was thinking that Quantum might not be worth the effort (smell), but the testimony here has me feeling like I should continue using it.


Ray, after my third or fourth use of my current bottle of Quantum I failed to tighten the top sufficiently and it lost the hydrogen sulfide that keeps it dormant. Do you think the biologically active contents die if the H2S is lost, or do they survive. I do keep it refrigerated.

-Keith

[Shadeflower]

thefish, wow now that is impressive root growth.

I agree that bacteria will play a big part in this too I'm sure. I have observed most problems in newly repotted orchids that could probably do with some good bacteria to help them settle in better.

I have concluded like has been pointed out to me that purpling can be a completely normal phenomena but at the same time it can be a sign the orchid is struggling a little.

I'm glad you guys have shed som more light on the matter for me.

Keith thank you for your invaluable observations. I hope to hear more on your trials in future.

[Ray]

Originally Posted by K-Sci

Hmm. I was thinking that Quantum might not be worth the effort (smell), but the testimony here has me feeling like I should continue using it.


Ray, after my third or fourth use of my current bottle of Quantum I failed to tighten the top sufficiently and it lost the hydrogen sulfide that keeps it dormant. Do you think the biologically active contents die if the H2S is lost, or do they survive. I do keep it refrigerated.

-Keith

The H2S is an activity suppressant. Losing it simply mens the shelf live is more likely months, rather than a year or more.

FWIW, in a few days I expect to have some Inocucor Garden Solution available, in addition to the Quantum-Total.

[isurus79]

Originally Posted by Ray

FWIW, in a few days I expect to have some Inocucor Garden Solution available, in addition to the Quantum-Total.

Damn, you just shipped an order of kelpmax to me this week. Now I'll have to make another order!!

[Dusty Ol' Man]

Originally Posted by isurus79

Damn, you just shipped an order of kelpmax to me this week. Now I'll have to make another order!!

Don't feel bad Steve. I missed the black Friday sale by 2 hrs!

[estación seca]

All the imported plants unboxed in the video have old but living roots able to absorb water. Older orchid roots turn light brown.

[Shadeflower]

I just realized I never showed the vanda at it's worst to properly compare it.

You might argue "These plants are grown in very high light and are imported directly from Brazil, hence the red leaves. That's how they look naturally."

but I prefer the leaves looking more green how they are now, including on my laelia pumila which has improved nicely too. It was only on Rainmix this started happening.

[isurus79]

Originally Posted by Shadeflower

I just realized I never showed the vanda at it's worst to properly compare it.

You might argue "These plants are grown in very high light and are imported directly from Brazil, hence the red leaves. That's how they look naturally."

but I prefer the leaves looking more green how they are now, including on my laelia pumila which has improved nicely too. It was only on Rainmix this started happening.

I’m not arguing. I’m pointing out how plants grow naturally. You are arguing that their natural pigment is unnatural. Your leaf color preference has no bearing on the plant’s metabolic processes.