# Orchiata



## Stone (Jul 10, 2013)

I just recieved 7 bags of Orchiata. I must say that on first sight I'm not overly impressed. It doesn't look much different from the radiata bark I've been using for years. But it does have a resinous smell (meaning its not aged very much) I don't know if this is a good or bad thing? I guess it should last longer if its not composted. Anyone see any root problems using it straight from the bag?


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## Eric Muehlbauer (Jul 10, 2013)

I have found Orchiata to be the best bark I have used in decades. It's consistent, does not break down quickly, and paphs usually show good root growth fairly quickly (but that may also be due to K-lite). Even though people say to use it straight, by itself, I still add spongerock, lava rock, and a little charcoal. It has calcium, but I still add some crushed coral for brachy's and parvi's. If anything, it seems to be the best medium I have found for brachy's. I always found brachy's to hate repotting...but they repot very well with Orchiata.


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## abax (Jul 10, 2013)

I use it straight from the bag for small plants and add charcoal and maybe
some hydroton for larger plants in clay orchid pots. I'm with Eric on this...
best product I've found in years. It works particularly well with K-Lite.


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## Trithor (Jul 11, 2013)

I wish we could get Orchiata here. The bark we get is used for landscaping (mulch) and is available as huge chunks which makes it unusable. As a by-product they generate smaller grades, but more often than not they are more flakes than chunks and so compact in the pots, again not a desirable situation.


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## JeanLux (Jul 11, 2013)

I use it straight from the bag since 6 months now, and esp. my catts and co like it a lot !!!! Ordered this time also one bag of super, and this is really suited to use as the outer layer in baskets!! Jean


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## limuhead (Jul 11, 2013)

I have been using it for about 6-8 years. While it is still the best bark on the market it is not as consistent as it was before. Recently I have been mixing it 1 part CHC, one part #5 Orchiata and one part #4 perlite. I have found this mix to be really good for my paphs, phrags, miltoniopsis, and anything from seedlings out of flask and compots; pretty much all genera. My cattleya go from this mix(overgrown in 2") into net pots with HUGE bark. Essentially 3 chunks fill up a 4 inch net pot. I can post some pics if anyone is interested; pretty much like a mount, but retains more moisture and won't rot when it rains for weeks at a time over here...


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## goldenrose (Jul 11, 2013)

I repotted a lot of different orchids, mostly paphs, last fall, all doing well & have order more. I mixed with charcoal, perlite, lava rock.


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## Ozpaph (Jul 11, 2013)

I have used it for a year and its great.
I used it straight from the bag.
Roots, everything very good.


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## Ozpaph (Jul 11, 2013)

limuhead said:


> I have been using it for about 6-8 years. While it is still the best bark on the market it is not as consistent as it was before. Recently I have been mixing it 1 part CHC, one part #5 Orchiata and one part #4 perlite. I have found this mix to be really good for my paphs, phrags, miltoniopsis, and anything from seedlings out of flask and compots; pretty much all genera. My cattleya go from this mix(overgrown in 2") into net pots with HUGE bark. Essentially 3 chunks fill up a 4 inch net pot. I can post some pics if anyone is interested; pretty much like a mount, but retains more moisture and won't rot when it rains for weeks at a time over here...



please show pictures.


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## Ray (Jul 11, 2013)

I agree with the "not as consistent as it was" statement. Still better than anything else out there, but not as uniformly graded as it used to be.


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## NYEric (Jul 11, 2013)

True Orchiata is good. i got some recently that had pieces of "I don't think so..." bark in it so I'm checking packages carefully when i get more.


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## Cheyenne (Jul 11, 2013)

Orchiata is good. But, there is always a butt. I used it for probably 3 to 4 years. I have to give a word of warning. When they treat it with dolomite solution it is for a reason. Pine bark has a lower ph to begin with. So they treat it to raise it up to acceptable levels. The first year I used it everything was great because I was using water with a good amount of alkalinity. Later I switched to just rain water and had been lazy with using any lime products. I noticed roots would begin then immediately die when they got into the mix. So I checked ph and it was considerably lower than pots with regular fir bark. So I tested it right out of the bag and it was alright. Then I put some in water for a few days then drained it and filled it up again to wash of the lime and the ph was really low. I think it has to do with the way it is composted, I believe they compost it for a year or something, then treat it with lime. Sam Tsui said he will not use orchiata any more after a few years of use Because of the ph issues. Other things grew great in it. Dendrobiums, cattleya, epidendrum, phrags all did fine not paphs. Also the roots won't stick to it like they do fir bark. They more grow along the top and around the sides, not down threw it well.


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## tomkalina (Jul 11, 2013)

Our experience has been similar to Cheyenne's; We also moved our Paphs and Phrags out of Orchiata back into our standard fir bark mix this spring because of poor root growth. In fact, we are months behind in releasing our compot list this year because we found that after one year in fine Orchiata mix, none of the Paph. or Phrag. compots had developed roots beyond the original flask roots.
While the long-petalled Phrag species adults seem to like it, all of the adult besseaes did not. Sparse roots circling the pot surface seemed to be the norm for besseae. 

The compots noted above were repotted into fir bark mix late this spring, but it'll be months before I expect to see good root development. Sam also told me about the Orchiata pH going down after a year and recommended I add dolomite lime to bring the pH back up, but I decided not to do this because we are using K-Lite. That's not to say that under conditions different from ours, or for different genera, Orchiata doesn't work - but for us it doesn't work as well as our standard fir bark mix for the genera we grow.


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## dodidoki (Jul 11, 2013)

I have no experience with this but I learned that there could be Rhizoctonia in any bark what can cause rot problems, so I desinfect any bark before using as potting media.


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## Cheyenne (Jul 11, 2013)

tomkalina said:


> Our experience has been similar to Cheyenne's; We also moved our Paphs and Phrags out of Orchiata back into our standard fir bark mix this spring because of poor root growth. In fact, we are months behind in releasing our compot list this year because we found that after one year in fine Orchiata mix, none of the Paph. or Phrag. compots had developed roots beyond the original flask roots.
> While the long-petalled Phrag species adults seem to like it, all of the adult besseaes did not. Sparse roots circling the pot surface seemed to be the norm for besseae.
> 
> The compots noted above were repotted into fir bark mix late this spring, but it'll be months before I expect to see good root development. Sam also told me about the Orchiata pH going down after a year and recommended I add dolomite lime to bring the pH back up, but I decided not to do this because we are using K-Lite. That's not to say that under conditions different from ours, or for different genera, Orchiata doesn't work - but for us it doesn't work as well as our standard fir bark mix for the genera we grow.



Right on Tom, I have done the same thing of moving back to regular mixes. I also thought at first maybe the plants just need to be repotted again even though the bark is not broken down.so I repotted into new orchiata and after months still no roots. So once spring came and weather warmed up I started checking a few plants. The lack of roots was frustrating. So I put a few back in regular fir bark and literally after one to two weeks I had roots on all the ones I repotted. Now I still have alot of it, so I am saving it for my other genera and I am using it in the firbark as you would use charcoal to keep the mix lasting a little longer. By the way catasetinae just love it.


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## Roth (Jul 11, 2013)

In short:

- The processing of Orchiata involves 'aging' the bark. Basically the bark is stored in piles that are turned for several months, until it becomes hydrophilic, volatile compounds are removed as well as some potentially toxic chemicals, as well as some organic acids. It is not a composting, that would involve using nitrogen to degrade the cellulose/lignin structure. In Orchiata, the cellulose/lignin structure is pretty much intact, hence its stability.

- Orchiata must be very easy to wet, as it is hydrophilic at the end of this aging process.

- At that stage, the complete stock is screened for debris or whatever, and to grade it.

- The lime is added just after the grading, to get a final pH that is suitable. It is not added at the aging process.

This said, again, ammonium nitrogen fertilizers give the best result, especially in Orchiata. In that case, and in my experience, the plant growth is maximal, and the roots keep growing. Using nitrate nitrogen is not so much of a good idea in Orchiata, or any media whose pH has been upped to the core by the addition of lime. At least, the growth is not optimal, in my, and others, experience.


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## Bob in Albany N.Y. (Jul 11, 2013)

Tom, so when you talk about adding dolomite lime are you talking about the everyday lime that we all add to our lawns? If that is correct and you had a greenhouse couldn't you just cast the lime around and then water it in once a year?


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## tomkalina (Jul 11, 2013)

Xavier - The problem is, many of us are using either MSU for R/O or K-Lite fertilizer, and they are nitrate based. If ammonia based fertilizers are required to produce optimal root growth in Orchiata, then we should go back to the old Peters 30-10-10 if we use it as potting medium. 

Bob - You have to ask Sam; He made the recommendation to add lime after a year to increase pot pH. We never did it because I wasn't happy with the root growth in Orchiata and decided not to add another variable to the cultural equation. 

In the final analysis, what works for you, works for you. If you're having good results with Orchiata, keep using it, but bear in mind the pH change after a years growing.


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## papheteer (Jul 11, 2013)

I bought some orchiata from Ray back in May. Repotted some seedlings in it last month and so far very little root growth. Usually with fir bark there's lots of root growth a month after repotting. Ill give it another month or 2, if i see noimprovements, ill repot in Douglas fir bark.


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## Stone (Jul 11, 2013)

Roth said:


> In short:
> 
> 
> 
> ...


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## Stone (Jul 11, 2013)

Ozpaph said:


> I have used it for a year and its great.
> I used it straight from the bag.
> Roots, everything very good.



Good to know:clap:


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## Stone (Jul 11, 2013)

limuhead said:


> I have been using it for about 6-8 years. While it is still the best bark on the market it is not as consistent as it was before. Recently I have been mixing it 1 part CHC, one part #5 Orchiata and one part #4 perlite. I have found this mix to be really good for my paphs, phrags, miltoniopsis, and anything from seedlings out of flask and compots; pretty much all genera. My cattleya go from this mix(overgrown in 2") into net pots with HUGE bark. Essentially 3 chunks fill up a 4 inch net pot. I can post some pics if anyone is interested; pretty much like a mount, but retains more moisture and won't rot when it rains for weeks at a time over here...



Ever notice that paph roots (and others too) seem to really take off when they hit the side of the pot? Someone in our club mentioned that he puts seedling right up against the side of the pot so the roots hit it quickly and go right down to the bottom. (looks a bit silly though) I think it has something to do with the flat, even surface that encourages them to keep going. Using big chunks in your catt pots are probably doing the same. Kind of like a slab of cork.
I had the same idea of using huge chunks of bark for paphs too. So you get lots of free air, lots of flat surfaces and you just addsome chopped moss and sand to hold the moisture. What else could you want!:rollhappy:


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## emydura (Jul 12, 2013)

Stone said:


> Ever notice that paph roots (and others too) seem to really take off when they hit the side of the pot? Someone in our club mentioned that he puts seedling right up against the side of the pot so the roots hit it quickly and go right down to the bottom. (looks a bit silly though) I think it has something to do with the flat, even surface that encourages them to keep going. :



Gary Hart spoke at our orchid meeting last week and said exactly the same thing. He highly recommends potting to one side rather than in the centre.

I have just started using Orchiata bark and are now a little concerned. Prior to this post I had never heard a negative thing about it. The MAGAMP fertiliser I use is ammonium nitrogen so hopefully the problems of low pH won't be a problem.


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## Stone (Jul 12, 2013)

emydura said:


> Gary Hart spoke at our orchid meeting last week and said exactly the same thing. He highly recommends potting to one side rather than in the centre.
> 
> I have just started using Orchiata bark and are now a little concerned. Prior to this post I had never heard a negative thing about it. The MAGAMP fertiliser I use is ammonium nitrogen so hopefully the problems of low pH won't be a problem.



If you keep an eye on the pour-through pH and add a bit of lime if you need to, everything should be fine. SHOULD!


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## Cheyenne (Jul 12, 2013)

The ph issue can always be corrected. But to me a real problem was how the roots didn't liketo grow down in the mix or stick to the pieces of bark. After you use it for a while you will see what I mean. I think the reason is that the inside of the bark stays hard making it last a long time but the outside is alot softer when it gets wet and stays moist. I don't think the root hairs can attach to ot well. Maybe this is do to the process they use to soften and age the bark. Fir bark stays hard enough for the first six months when new roots are growing that the hairs have a chance to attach. Maybe if the roots can't attach well to a surface they are reluctant to continue growth, I am not sure. But the only plants that I had attach to the bark were some brachy's with there long root hairs. Sometimes I tried to add ALOT of perlite and had better results, but I think that was due to the roots attaching to the perlite morw than the bark. 
I was also using a fertilizer with alot of ammonical nitrogen. It helped a little bit. But it will also speed up the process of making the ph drop further. So you have to be diligent with the lime applications. 

I am interested in hearing other peoples results after they use it for a while and have a chance to repot after a year or so.


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## Ray (Jul 12, 2013)

I have been using Orchiata for about 2.5-3 years now, have used MSU and now K-Lite exclusively, have done nothing to adjust the pH, and I am seeing absolutely no issues with root growth. The plants that I have used it on tend to be in baskets, but I have several paphs from Graham at Lehua that I have not moved out of the plastic pots they came in, and are older than that, and they are cranking along too.


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## Rick (Jul 12, 2013)

Roth said:


> In short:
> 
> 
> - The lime is added just after the grading, to get a final pH that is suitable. It is not added at the aging process.



Are you sure? I thought I read in their company litterature that the dolomitic lime was added during the "aging process" .

In some ways this made it analagous to the pretreatment process that ANTEC recomended for coconut husk chips with calcium nitrate and mag sulfate


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## SlipperFan (Jul 12, 2013)

This is an interesting thread -- like David, I've never heard a bad thing about orchiata until now. I have my Paphs and Phals potted in a mix of orchiata, sponge rock and PrimeAgra for two years now, and I'm not seeing any root issues, either.


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## naoki (Jul 12, 2013)

Is the pH of Orchiata lower than Fir bark? I looked around a little bit, but there seems to be a mixed info. According to one scientific study, where Orchiata No. 5 was soaked in water over night before the experiment, and followed the pH over 7 months, initial pH was 4.8 and declined only a little bit to 4.2. If washing off of lime is an issue, you expect the decline of pH to be faster than other media, but it wasn't any faster than other media. The authors think that things excreted from roots are the main cause of pH decline.


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## Paphman910 (Jul 12, 2013)

I read on an article of an experiment and it says Douglas Fir ph is 4.2


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## naoki (Jul 12, 2013)

OK, I found an answer from a scientific experiment. pH of fir bark is around pH 6.54 initially, and decline to 5.45 after a year (with Phal growing in it). So Orchiata has a little lower pH than fir bark.

Source of this info for fir bark: http://hortsci.ashspublications.org/content/33/2/247.short
For Orchiata: http://hortsci.ashspublications.org/content/46/7/1022.abstract

Thanks Paphman, maybe there is some variation among Doug Fir bark. Also, different method of measuring pH may influence. I think the two studies I cited use somewhat similar method (pour through), so they may be comparable.


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## DavidCampen (Jul 12, 2013)

I just tested some Pinus radiata bark that I purchase from Sunset Valley Orchids:
http://www.sunsetvalleyorchids.com/htm/bark.html

I put #3 bark into a 250 ml beaker to the 100 ml mark and added RO water to the 200 ml mark. After several minutes of gentle agitation I measured the pH using an "Oakton EcoTestr pH2" handheld pH tester that had been calibrated earlier in the day against pH 4.01 and pH 7.01 calibration buffers. I measured a pH in this bark water slurry of 4.0. After this measurement the pH tester was verified against pH 4.01 and pH 7.01 calibration buffers. I have labeled and covered the beaker of slurry and will leave it on my workbench.

I have some Douglas Fir bark but it is in a rented storage room and I won't be able to get there until next weekend. I will test this as soon as I can.


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## keithrs (Jul 12, 2013)

There was a video that showed the process of how orchiata is made. In the video they explained that they wet the piles of bark with dolomite lime. They explained that wetting the piles with lime allows the lime to work it's way into the bark and forms a "shell" on the bark and keeps the bark for composting. Not sure if they have changed there ways with demand here in the states for this bark(or some other reason) and this is why folks are see issues? I personally have not seen issues.


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## Roth (Jul 13, 2013)

DavidCampen said:


> I just tested some Pinus radiata bark that I purchase from Sunset Valley Orchids:
> http://www.sunsetvalleyorchids.com/htm/bark.html



That's a totally different product, it is fresh Pinus radiata bark, not processed in any way, just screened for the size. Expect it to be acid, and not much water retentive. 



naoki said:


> OK, I found an answer from a scientific experiment. pH of fir bark is around pH 6.54 initially, and decline to 5.45 after a year (with Phal growing in it). So Orchiata has a little lower pH than fir bark.
> 
> I think the two studies I cited use somewhat similar method (pour through), so they may be comparable.



Fir bark is much more acid to start with, however when fresh, it is water repellent. If you put a sample in water, it floats, and does not become wet. As a result, it is difficult to assess its pH in the first place. But clearly, fir bark never starts at pH 6.54, it is technically impossible.

Apart from the problem of putting water repellent bark in water, and 'checking the pH', another common misconception is that, in some instances, weathered composted barks have been leached of their acids, and can have a higher pH ( but not a good stability...). In a few cases, when you buy 'horticulture bark', it is fresh bark, correct, but already pre limed at the factory. It is especially common in Europe, I don't know how it works in the USA... The lime will give the false impression that the bark is more 'alkaline', however as, again, it is water repellent, the lime is on the outer layer of the chip. As a result, after some weeks, the pH drops, especially for growers that tend to flush abundantly.



Rick said:


> Are you sure? I thought I read in their company litterature that the dolomitic lime was added during the "aging process" .
> 
> In some ways this made it analagous to the pretreatment process that ANTEC recomended for coconut husk chips with calcium nitrate and mag sulfate



I am really sure, because I work for Besgrow :evil: The dolomitic lime is added at the end of the aging process if you want, which means the bark is aged, screened, and the lime is added after screening. There is still residual moisture at that time, and the lime sticks easily. As well, the quantity of lime to apply for the small grade is not the same as the one to apply for the biggest grades. The purpose is to end up with Orchiata at a pH that is not too acid, and not too alkaline...

The pretreatment process for the coconut is something that I designed for the coconut husk chips nearly 20 years ago. Antec got the info from the old AOS forum at that time, just to put the records straight ( and at first they did not believe sodium could still be in the chips without being dissolved by water... until they experienced major plant losses and setbacks, which pushed them to make the proper analysis). This said... it has a different purpose, which was to exchange the potassium and sodium with calcium and magnesium, to remove the sodium from the coconut chips. But it cannot compare with the orchiata and added lime in fact.


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## Stone (Jul 13, 2013)

It doesn't really matter what the pH of the fresh bark is as long as its properly adjusted and kept that way.
For example: For every Kg of Urea you use, you must add 0.75Kg of Calcium carbonate to restore pH.
For Ammonium sulphate, you need 1.1 Kg and for Ammonium nitrate only 0.5Kg of Calcium carbonate for every Kg of the fertilizer.


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## Trithor (Jul 13, 2013)

Whew, this bark thing is very complicated. I just buy a bag of bark chips, make a basic mix, pot my plants and hope for the best! Perhaps that is why I don't grow very well?


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## Bjorn (Jul 13, 2013)

Stone said:


> It doesn't really matter what the pH of the fresh bark is as long as its properly adjusted and kept that way.
> For example: For every Kg of Urea you use, you must add 0.75Kg of Calcium carbonate to restore pH.
> For Ammonium sulphate, you need 1.1 Kg and for Ammonium nitrate only 0.5Kg of Calcium carbonate for every Kg of the fertilizer.



I am delighted to see that Xavier is back, Lets hope its not only for this job-related occasion. Here's my two cents worth regarding the pH issue in particular the urea-misconception as I call it. Ok, here it comes:
"everyone" knows that if you use urea the pH drops. But is it really so? Having a chemistry background, working wit it for 30 years, I simply cannot make that consistent with the basic chemical reactions that the urea undergoes through the transformation to ammonium and eventually to nitrate, if it does? What I experience if I let a diluted, say 100ppm, urea solution stand for a couple of days, is that the pH increases. This can be attributed to the enzymatic decomposition of urea into ammonia, which of course reacts with water to ammoniumhydroxide which is basic.
The ammonium part of the ammoniumhydroxide may in turn be transformed to nitrate, but is it not more likely that the plant absorbs the ammonium? After all if it has nitrate it has to reduce it to ammonium in order to use it? So, my question is therefore; where is the acid that has to be neutralised?
Using ammonium salts like ammonium sulphate is another story. The ammonium ion reacts acid with water and here we have acid, but this is not urea.
Comments?


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## Rick (Jul 13, 2013)

Trithor said:


> Whew, this bark thing is very complicated. I just buy a bag of bark chips, make a basic mix, pot my plants and hope for the best! Perhaps that is why I don't grow very well?



That's the same reason 3/4 of my plants are either mounted or in baskets with little or no organic media (including slippers).

Same reason folks are using SH methods.

Pot management for orchids is much more of a nightmare than it needs to be. Heavy fertilizing just compounds the issues.

Most of our favorite species grow on the sides of trees with no media at all. Roots exposed to wind sun and rain, and they do just fine.

Keeping orchids in pots is like keeping fish in an aquarium. Most of the effort to keeping the fish in good shape is maintaining the filtration system and water quality, and most of the problems are due to overfeeding.


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## Trithor (Jul 13, 2013)

I spend most of my time trying to uncomplicated things, and also attempting to make things as 'idiot proof' as is possible (as John pointed out not too delicately, I do tend to idiocy). I find that as my collection increases in size and variety, and while I remain full time employed and still need to find time to run the game ranch, that I need to simplify my growing as much as possible. I never realized that bark was such a complicated variable, I must say it makes me feel somewhat silly and poorly informed!


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## gonewild (Jul 13, 2013)

Trithor said:


> I must say it makes me feel somewhat silly and poorly informed!



That's why the hydroponic folks stopped using organic media.

Never will there ever be two trees with the exact same chemical content, so why do we assume every bag of bark would be the same.


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## goldenrose (Jul 13, 2013)

Trithor said:


> I spend most of my time trying to uncomplicated things, ....
> I need to simplify my growing as much as possible. I never realized that bark was such a complicated variable, I must say it makes me feel somewhat silly and poorly informed!


This thread is not what I expected, I'm a K.I.S.S. person, I'm stickin' to what works for me & if it's not, then I'm aware of other possibilities.



Trithor said:


> Whew, this bark thing is very complicated. I just buy a bag of bark chips, make a basic mix, pot my plants and hope for the best! Perhaps that is why I don't grow very well?


I doubt it, orchids can be pretty adaptable!


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## orcoholic (Jul 13, 2013)

It seems that everyone adding lots of amendments to the Orchiata are not having many problems with it regardless of whether they use ammoniacal or nitrate nitrogen.

Ray mentioned he's been using Orchiata for several years, but i'm pretty sure he grows most things in SH. The material from Lehua may not be in Orchiata, or may have a lot of amendments. 

Quintal uses Orchiata, but adds a lot of sponge rock. I repotted a group of Den. lowii I got from them into my orchiata mix, and they just kept shriveling and died. I thought it was just some bad plants, but now i'm rethinking it. The plants came in looking fine, like most of their orchids. The same thing happened to an Epi with a clonal name of Flame Thrower (Can't remember the full name).

Is anyone actually using Orchiata with a fertilizer where the N is mostly Ammoniacal and has been using it for a couple years? It would be good to hear from someone with actual experience. My fertilizer has all Nitrate and I add Calcium Nitrate. I am also in my first year of using Orchiata.


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## Roth (Jul 13, 2013)

orcoholic said:


> It seems that everyone adding lots of amendments to the Orchiata are not having many problems with it regardless of whether they use ammoniacal or nitrate nitrogen.
> 
> Ray mentioned he's been using Orchiata for several years, but i'm pretty sure he grows most things in SH. The material from Lehua may not be in Orchiata, or may have a lot of amendments.
> 
> ...



Lehua is using only Orchiata so far... 

For Orchiata with ammoniacal fertilizer, I do indeed use it, and so are all the Japanese. Most of the Orchiata customers growing phalaenopsis, and most of the hawaiians are using as well an ammoniacal fertilizer...

For Dendrobium lowii, it is typically one species that does not respond well to calcium nitrate at any time. I grow them too, but calcium nitrate make them drop their leaves pretty quickly for me... I use a high ammonium ratio fertilizer, and they show no problem. They do not like to dry too, and as a bonus, they must be repotted at the right time, when new roots appear at the base of the new growth. Not before, and for sure not when the new growth just emerges... That's the main cause of death for lowii ( and spectatissumum as well as sculptum, which have similar requirements...).


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## Stone (Jul 13, 2013)

Bjorn said:


> I am delighted to see that Xavier is back, Lets hope its not only for this job-related occasion. Here's my two cents worth regarding the pH issue in particular the urea-misconception as I call it. Ok, here it comes:
> "everyone" knows that if you use urea the pH drops. But is it really so? Having a chemistry background, working wit it for 30 years, I simply cannot make that consistent with the basic chemical reactions that the urea undergoes through the transformation to ammonium and eventually to nitrate, if it does? What I experience if I let a diluted, say 100ppm, urea solution stand for a couple of days, is that the pH increases. This can be attributed to the enzymatic decomposition of urea into ammonia, which of course reacts with water to ammoniumhydroxide which is basic.
> The ammonium part of the ammoniumhydroxide may in turn be transformed to nitrate, but is it not more likely that the plant absorbs the ammonium? After all if it has nitrate it has to reduce it to ammonium in order to use it? So, my question is therefore; where is the acid that has to be neutralised?
> Using ammonium salts like ammonium sulphate is another story. The ammonium ion reacts acid with water and here we have acid, but this is not urea.
> Comments?



Bjorn, I certainly have no chemistry background and far be it for me to know exactly what goes on but according to my reference ( and lets face it, thats all we have unless we have a lab and can do the experiments ourselves ) the Urea added to the media will transform to ammonium carbonate within 2 days
The reaction for ammonium is given as NH4+ + 202 (to) NO3- + H2O + 2H+ (You can explain that to me later:rollhappy
So Loss of nitrate added as nitrate does not alter the pH BUT loss of nitrate produced from ammonium will do so. So it is claimed that acidification is due more to this effect than the direct effect of ammonium. In short loss of nitrate from ammonium by leaching every time we water = acidification.
It is also claimed that this acidification can be prevented by use of fertilizers where the nitrate to ammonium ratio is 2 or 3 to 1. But I prefer to use higher urea/ammonuim than nitrate and add lime.
But lately I've been turing my attention more and more towards organic N forms and hopefully doing away with nitrate and ammonium additions? After all its more what the paphs have evolved with and its so difficult to get the balance just right with concentrated fertilisers. Maybe a combination??? As you know the late Jim Rentoul used only blood and bone twice a year and a calcium hydroxide drench twice per year and that's it!! (but he also put oak leaves in his mix which may have the best balance of nutrients?)


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## DavidCampen (Jul 13, 2013)

DiAmmonium Phosphate (DAP) is a readily available fertilizer material; it has a pH of about 8 and the pH could be adjusted further with phosphoric acid based pH Down to produce a good buffer with a pH in the range of 6 - 8. A solution of this might be usefull as a soak for modifying the pH of bark.


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## Bjorn (Jul 14, 2013)

Stone said:


> Bjorn, I certainly have no chemistry background and far be it for me to know exactly what goes on but according to my reference ( and lets face it, thats all we have unless we have a lab and can do the experiments ourselves ) the Urea added to the media will transform to ammonium carbonate within 2 days
> The reaction for ammonium is given as NH4+ + 202 (to) NO3- + H2O + 2H+ (You can explain that to me later:rollhappy
> So Loss of nitrate added as nitrate does not alter the pH BUT loss of nitrate produced from ammonium will do so. So it is claimed that acidification is due more to this effect than the direct effect of ammonium. In short loss of nitrate from ammonium by leaching every time we water = acidification.
> It is also claimed that this acidification can be prevented by use of fertilizers where the nitrate to ammonium ratio is 2 or 3 to 1. But I prefer to use higher urea/ammonuim than nitrate and add lime.
> But lately I've been turing my attention more and more towards organic N forms and hopefully doing away with nitrate and ammonium additions? After all its more what the paphs have evolved with and its so difficult to get the balance just right with concentrated fertilisers. Maybe a combination??? As you know the late Jim Rentoul used only blood and bone twice a year and a calcium hydroxide drench twice per year and that's it!! (but he also put oak leaves in his mix which may have the best balance of nutrients?)



Thanks Mike,
This does explain it at least to some extent. Forgot about the carbonate part of the urea I do agree that nitrate run-off may produce some acidification by this mechanism, but I am uncertain whether the conditions that apply to soil would apply in our mixes? Whether the ammoniumcabonate from the urea produces an acid reaction or not seems to be the decisive point here. I do not know, but has a gut-feeling that it may give some alkaline reaction. At least that is what I measure on a dilute mix if let standing for a few days. 
Another thing that may look silly is to put so much emphasis on this matter as long as we heavily flush our mixes, the explanation for the excellent results obtained with ammonium in the fertilizer is probably because the easy access for the plant. Because of the regular flushing, I do have my doubts about the conversion to nitrate as well. 
I do adjust the pH of the water I use, so in my case, this may be the main pH influencing factor. Btw. I strongly suggest that everyone should adjust their pH, as else soft and suitable tap water often is adjusted to a pH of approximately 8 with sodium hydroxide or similar to prevent corrosion.
I have attached a dosmatic proportioner to my watering line so I have to use soluble fertilisers. Else, the ideas of Jim Rentoul still stands for me as prominent examples on how things can be done. I have all his books I believe, they are getting difficult to find these days.
Bjorn


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## weiweidc (Jul 14, 2013)

Has anyone tried Kiwi bark? How does it compare to Orchiata?


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## paphreek (Jul 14, 2013)

weiweidc said:


> Has anyone tried Kiwi bark? How does it compare to Orchiata?



I have used both with good results, so far. However, I prefer the Kiwi bark for two reasons: It is harder and less moisture retentive, which I prefer because of my high humidity in the greenhouse, and more importantly, the fine Kiwi Bark is a little smaller than the Orchiata Classic, and holds small Paph seedlings in place better. This allows the roots to establish themselves and grow more quickly. 

That being said, if I were in a dryer growing space such as the house, I would probably use the Orchiata more and amend it with a small amount of CHC (for moisture retention) so I wouldn't have to spend as much time watering.

Good thread, BTW! Even though I'm reasonably happy with the growth of my plants, there is always room for improvement.


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## Ray (Jul 14, 2013)

orcoholic said:


> Ray mentioned he's been using Orchiata for several years, but i'm pretty sure he grows most things in SH. The material from Lehua may not be in Orchiata, or may have a lot of amendments.


About half my plants are grown in S/H culture using LECA; about another 25% are in straight Orchiata.

The plants I get from Lehua are in Orchiata plus about 10% spongerock, but I don't see that having much effect on the media chemistry.


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## Rick (Jul 14, 2013)

Bjorn said:


> Thanks Mike,
> This does explain it at least to some extent. Forgot about the carbonate part of the urea I do agree that nitrate run-off may produce some acidification by this mechanism, but I am uncertain whether the conditions that apply to soil would apply in our mixes? Whether the ammoniumcabonate from the urea produces an acid reaction or not seems to be the decisive point here. I do not know, but has a gut-feeling that it may give some alkaline reaction. At least that is what I measure on a dilute mix if let standing for a few days.



The acidification is due to nitrifying bacteria (under oxic conditions) converting ammonia to nitrate. There are lots of water retentive pores in the bark matrix (which is why we use bark/moss/chc in the first place), that are chalked full of bacteria/fungi doing all kinds of stuff from nitrifying/denitrifying/plane old respiration from carbon degradation. 

Non biological chemistry is minimal in the pot matrix. There's really not anything going on that isn't already known and quantified in a waste water treatment plant.


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## Ruth (Jul 14, 2013)

I have most of my orchids in Orchiata. All of them seem to be doing fine, except for one Masd. coccinea, which I had repotted about a month ago into Orchiata. I think that I used the bottom of the bag of Orchiata and there must have been some concentration of the lime in the bottom of the bag. Part of the leaves would turn gray and dry up. I repotted it in sphag and it is doing fine now. The other thing I see is that when you repot with the dry Orchiata mix, it is hard get it to moisten up, especially the top layer of the potting mix. That said, I will continue to use Orchiata.


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## Paul (Jul 14, 2013)

I just started to repot my plants in Orchiata. Looks like a very good bark. Easy to pot with, easy to wet just after repoting. I use 3 grades, depending on the plant size and species. for Paphs, only the Classic and Power.
I will tell about the results in a few months!! This is the good time to repot paphs, many new roots are starting now!

The maybe good thing is that my fertilizer is ammonitrate based... with low K and P  and low to average alcaline water.


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## limuhead (Jul 14, 2013)

weiweidc said:


> Has anyone tried Kiwi bark? How does it compare to Orchiata?



I use it and it works fine. Not sure if it lasts as long because it is not composted. Composting any bark is pretty easy. I compost my large chunky bark by soaking it for a day, then coating it with Dolomite and then let it sit for a few weeks or until the dolomite has completely dried. I then rinse it and use it. So far I have had excellent results as far as roots attaching themselves to the bark.


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## orcoholic (Jul 14, 2013)

Roth said:


> Lehua is using only Orchiata so far...
> 
> For Orchiata with ammoniacal fertilizer, I do indeed use it, and so are all the Japanese. Most of the Orchiata customers growing phalaenopsis, and most of the hawaiians are using as well an ammoniacal fertilizer...



What fertilizer are they using?

Also, I grow a lot of phals in NZSM. Will an ammoniacal based formula harm them?

Roth - thanks for the type on the lowii's.


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## Stone (Jul 15, 2013)

Xavier! While you are reading this, A question.
In an old post you mentioned doing leaf analysis of some emersonii and mastersianum etc. and you reported High nitrate and low Mo in the chlorotic plants and also low Fe and higher Mn, B and Zn in the wild plants. 
My question is did you do a sutstrate analysis? (habitat soil). How did it compare with the leaf analysis of the wild plants?
Only answer if you want to


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## Stone (Jul 15, 2013)

Paul said:


> I just started to repot my plants in Orchiata. Looks like a very good bark. Easy to pot with, easy to wet just after repoting. I use 3 grades, depending on the plant size and species. for Paphs, only the Classic and Power.
> I will tell about the results in a few months!! This is the good time to repot paphs, many new roots are starting now!
> 
> The maybe good thing is that my fertilizer is ammonitrate based... with low K and P  and low to average alcaline water.



I repotted some plants in it this week too. I agree I think its going to be good!
But instead of mixing smaller and large grades I have been making a mix with 4bark, 1 charcoal, 1 chopped moss, 1/2 chopped oak leaves and some sand. I know people say to use it straight but I really like the way this mix behaves in the pot! Lots of air but still good moisture. I think I finally found ''my mix''I will also report results later.


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## Ozpaph (Jul 17, 2013)

I thought oak leaves were quite acidic?


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## Stone (Jul 17, 2013)

Ozpaph said:


> I thought oak leaves were quite acidic?



Yes but no more than sphag or peat. Are you using straight bark for everything?


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## Ozpaph (Jul 20, 2013)

Stone said:


> Yes but no more than sphag or peat. Are you using straight bark for everything?



no. paphs - 50% orchiata, equal coarse perlite/charcoal/CHC
Catts - 60% bark, 30% charcoal, 20% CHC


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## Rick (Jul 20, 2013)

Stone said:


> Yes but no more than sphag or peat. Are you using straight bark for everything?



Have you had a chance to read that article that Naoki linked? Sphag is only initially acidic. If you don't add fertilizer the acidity washes out after a few months of watering. The strong and chronic drop in pH in sphag is due to the bacterial buildup from adding plant roots and regular feeding.

The effect in bark is less, I assume the effect in lime/dolomite impregnated Orchiata is even less.


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## limuhead (Jul 26, 2013)

Here is what seems to work for me.
Step 1 soak Kiwi Bark over night, drain well and and put in a container to mix.




Step 2 Add dolomite




Step 3 mix thoroughly making sure you have an even coat.




Step 4 Drill 1/4 inch holes in a trash can




Step 5 Fill with media and let sit for a week




Seems to work pretty well, never had any problems and my plants grow like weeds. I think the amount of dolomite depends on how much you water or how much rain you get. Growing in the rain seems to make the ph drop so the more you water/fert the more is needed.


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## limuhead (Jul 26, 2013)

Ozpaph said:


> please show pictures.



This is a Formosum Dendrobium hybrid, Thomas Warne x schutzei. Blooms last about 3 or 4 months and for me it blooms 2x a year. It is in a 3.75 net pot and I think there are either 3 or 4 pieces of large decorative bark in it that I 'composted' myself with dolomite.














The roots come out of the bottom, make a U-turn and go right back in the net pot...


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## SlipperKing (Jul 26, 2013)

Why do you put it in a trash can for a week? Does it get rained on?


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## limuhead (Jul 26, 2013)

SlipperKing said:


> Why do you put it in a trash can for a week? Does it get rained on?



I am not sure how long it takes the dolomite to penetrate the Kiwi bark. If you have ever used it the bark is extremely hard and dense. I just figured it would help to let it stew for a while. After the first watering a good part of the dolomite rinses out; I use net pots or pots with really good drainage and about 1/3 of my media is coarse perlite so there is no accumulation of excess dolomite.


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## limuhead (Jul 26, 2013)

And yes, it gets rained on quite a bit, so it does get rinsed...


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## Stone (Jul 27, 2013)

limuhead said:


> Here is what seems to work for me.
> Step 1 soak Kiwi Bark over night, drain well and and put in a container to mix.
> 
> 
> ...



 Wow man!! thats a HUUUUUGE amount of dolomite!


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## Ozpaph (Jul 27, 2013)

do you ever test the pH of the run-off early after potting?


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## limuhead (Jul 27, 2013)

Ozpaph said:


> do you ever test the pH of the run-off early after potting?



I don't own a ph tester. I do know from experience and from working with/for some large commercial nurseries that too much dolomite is fairly easy to fix. It just takes time. Dolomite overdose just stalls your plants in my experience. I have never lost a plant due to too much dolomite...


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## keithrs (Jul 29, 2013)

I tried the dolomite addition but it turned into a moldy mess. I tried it on pine seedling bark that I soaked in "liquid dolomite" for three days then left it to dry. A week later the pile was a moldy mess!


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## Ozpaph (Jul 30, 2013)

Did you dry it in the sun?


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## Roth (Jul 30, 2013)

keithrs said:


> I tried the dolomite addition but it turned into a moldy mess. I tried it on pine seedling bark that I soaked in "liquid dolomite" for three days then left it to dry. A week later the pile was a moldy mess!



I am back from New Zealand in fact where I was visiting the Orchiata and the Sphagnum factories...

So far that's why Orchiata is made with Pinus radiata, many types of pine/fir bark do not react well when their pH is increased, and it turns moldy after a while. The more lime, the fastest the decay.

The issue with adding lime on fresh Pinus radiata ( that's what Kiwi bark is in fact, fresh Pinus radiata bark) are first an increase in soluble organic and inorganic salts to start with, then, it will not remove the tannins and terpenes. Whilst it appears some of those compounds may promote orchid growth, many will stunt the growing. If you add a lot of lime and process it like Limuhead is doing, then you can get something acceptable, but first it costs money to add so much lime to start with, second the process cannot be done on a large scale, and it is hard to control the pH afterwards. With the same quantity of lime on fresh bark, some batches will end up with a pH of 7.2, some with pH over 8, some at 6...

That's why we prefer for the Orchiata to remove during the 'aging' as much acids and unwanted organic chemicals, then check the pH of the batch, and apply lime at the end, to end up with a good pH. Adding a lot of lime is fine ( I do sometimes), but with some fertilizers only. Others ( the all nitrate ones are an example) will keep the potting mix at a pH level too high, and deficiencies will appear.


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## limuhead (Jul 30, 2013)

That was 2 bags of Kiwi bark, about 100 liters or just over 3.5 cubic feet, to which I added about 4 pounds of AG 65 dolomite. The dolomite that I get costs about $11.00 for a 50 pound bag. The Kiwi bark costs me $16.00 a bag, Orchiata is a bit more, so this is what I do when Orchiata is not in stock, which is fairly often. I used to buy it by the pallet but for some reason here in Hawaii ants love to set up house in the bags if it sits for more that a few months. If I have a pallet shipped in from the Big Island I can get Orchiata at about $13.50 per bag, but I have to buy 40 at a time. I go through about 20 bags a year and don't have room to store it, so I would rather pay more than have to deal with the ants...


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## limuhead (Jul 30, 2013)

Just out of curiosity Roth, do you think soaking the fresh(Kiwi bark) pinus radiata and dosing it with dolomite for a week going to help with the tannins and whatnot? My orchids don't seem to notice the difference, but I am growing in the rain and Kiwi bark seems to last a bit longer for some reason. Truth be told I would rather use the Orchiata, since I usually end up repotting long before the media breaks down; one of the disadvantages of having good growing conditions that allow rapid growth...


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## NYEric (Jul 30, 2013)

limuhead said:


> ..one of the disadvantages of having good growing conditions that allow rapid growth...



Son of a _ _ _ _ !!


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## wjs2nd (Jul 31, 2013)

NYEric said:


> Son of a _ _ _ _ !!



Haha, damn Hawaii growers. 

I've been using Orchiata for 2 years or so. No problems with great root growth. I use RO water I get from a organic market co-op (the filter is changed every 6 months and k-lite fertizilier.


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## limuhead (Aug 1, 2013)

I have been doing some experimenting, a little 'research' , and by research I mean asking some of the better commercial growers here in Hawaii and of course, reading some of the nutrition posts here on SlipperTalk, I have come to a few conclusions about Orchiata. First and foremost, through personal experience and posts here I think that Orchiata works better with ammonia/urea based fertilizers. I know many of the paph/phrag growers that contribute on this site are having success with K-lite but I am wondering if long term use of K-lite, MSU(or any other nitrate based ferts) on Orchiata may be the reason for root issues because of ph dropping. Second, I find that using the ammonia/urea based ferts are great for rapid vegetative growth and pushing seedlings(>3 inch pots) but without sufficient sunlight too much rapid growth leads to soft plants that are very vulnerable to pests and diseases. Calcium seems to help with these issues and because Orchiata has calcium added it may help to eliminate problems. And last, I am pretty sure that success growing with Orchiata has a lot to do with what is in the water that you use and how long your plants are in the pots. My plants are never in the same media for more than 15 months or so. To my knowledge I do not have issues with salt build up or media breaking down. I prefer not to use fir bark other than large chucky pathway bark because of mold/bacteria, or foul smelling media that over time seems to never dry out. I have not had any issues with Orchiata not drying out and I feel that it is easier to control moisture using it that other barks.


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## Stone (Aug 1, 2013)

limuhead said:


> > I know many of the paph/phrag growers that contribute on this site are having success with K-lite but I am wondering if long term use of K-lite, MSU(or any other nitrate based ferts) on Orchiata may be the reason for root issues because of ph dropping.
> 
> 
> 
> Nitrate won't drop pH. If anything it will raise it slowly over time. Ammonium will (especially ammonium sulphate) hense the need for extra lime with those kinds.


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## limuhead (Aug 1, 2013)

I have never had any issues of ph going up to my knowledge. I don't own a ph tester but have in the past used test strips to test the run off out of my pots. Like I stated earlier my plants are never in the same pot for more than 15 months, at the most; more like 8 months as I am rebuilding my collection and most are seedlings. I have a soil ph test kit. If I put pieces of my bark in it will that work? Any suggestions?


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## Stone (Aug 1, 2013)

Yes it will work. I've done that many times and its quite accurate (for our purposes anyway) but your plants are growing that well why bother?


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## Rick (Aug 1, 2013)

limuhead said:


> but I am wondering if long term use of K-lite, MSU(or any other nitrate based ferts) on Orchiata may be the reason for root issues because of ph dropping.



What's your definition of "long term". 

Did you read that paper that Naoki posted?

I'm not using Orchiata, and quit using pH adjusting pot amendments in whatever is still in baskets or pots about a year ago. I even switched back to a lot more use of CHC. 

I'm getting better root growth in CHC based mixes than I used to ever get at high feed rates with MSU, and some of these new test conditions are over a year now.


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## limuhead (Aug 2, 2013)

I would say long term, for me anyway is more than 12 months. I have been adjusting my media over the last year, as I have moved to a new place. 1,100 feet higher, maybe double the rainfall, more wind, less sun, and much cooler. So far the mix I am using is 2 parts pinus radiata, one park CHC, and one part #3 perlite. This is adjusted from my previous mix of equal parts of the same components. Before that it was 2 parts Orchiata to 1 part #3 perlite. Today I potted about 30 assorted Phrags from 2" up to 4". All had great roots with new ones starting more often than not. None of the media appeared to be breaking down; they went from plugs to 2" about 6 months ago. I think they were about 8 months out of flask when I got them. I have noticed a significant growth spurt in all of my plants when I switched to a ammonia/urea based fertilizer, I can't recall seeing that kind of improvement using any other type of fertilizer with Orchiata...


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