on the topic of charcoal

I ran across this broadcast NHK program. I found it worth while watching and gives some understanding as to it's horticultural use.
https://www.youtube.com/watch?v=jiVmKC8xXJ8

you can thank me later

I have to say I had NO idea of the varied uses for charcoal. Bravo to them!

Ok, it's later now. Thanks Dick!

From the webpage of William Valavanis

Shunka-en Bonsai Museum of Kunio Kobayashi
http://valavanisbonsaiblog.com/2015/02/11/shunka-en-bonsai-museum/

Thanks for sharing, Nellie. I've learned some good things today. Biochar looks like it's widely available. What about simply using incompletely consumed wood out of the fireplace?

I do not have any special knowldedge so I cannot say.
I now use charcoal (on the recently repotted trees of mine) for the purpose of its qualities regarding purification of water. But I wonder should the entire surface of the substrate be covered with charcoal pieces...?
Though looking at the photos from Shunka-en this is not the case, I mean we can see empty space on the surface.
It is also used for altering the ph of the substrate.
I hope somebody knowledgeable will offer more accurate information on the  subject

Thank you very much for this very interesting link Alexandra.

Like others, I've used some activated charcoal in my soil mixes for some time, but how they use it in so many ways in Japan is quite fascinating.

Glad to be of use to my bonsai fellows.
"Bonsai No Kokoro"

In my last reppoted trees, i used small pieces of charcoal mixed with the soil.

I have seen old netsuke with the shape of charcoal...very lovely.   In Japan earlier this year, did they give free charcoal hairchampoo to the guests....it was black, and I dared not try it  

Kind regards Yvonne

So here is a question/observation with using charcoal with bonsai...   I am also an aquarist and as many of you are probably aware charcoal/activated carbon is also used to help chemically filter water in aquariums.   Here is the problem that I see...charcoal is great at absorbing toxic minerals but overtime it is also just as good at releasing those toxins back to the environment.  This is why aquarists change charcoal frequently...like once a month.   More than 20 years ago, my partner and I did a series of tests with charcoal as a filter medium in relation to long term use and the dumping back of absorbed toxins..  What we found completely supported the fact that carbon does absorb but also will release after an undefined period (weeks to months usually) of use....thus making it imperative that it is changed or reactivated frequently when used in aquarium filtration.  

Therefore, I have to wonder how wise it is to use charcoal as a typical soil component.  I think it would be ok to use temporarily on top of the soil...like pictured above....as long as it is removed/replaced reasonably quickly. But, I am highly suspect of the long term effects of charcoal in the substrate.

If your only purpose for using charcoal is purifying water...I am of the belief that using your bonsai's substrate as the filter medium for the long term is a bad idea and could result in a dump of toxins in your soil....who knows how that might effect your tree??  Besides...at best, even activated charcoal will only effectively remove toxins for a period of weeks and in bonsai soil it is going to remain for years???  Filter your water if that is what it needs, but do it before it reaches your trees to be completely safe.

I would also never assume that charcoal you may make yourself and activated carbon are interchangeable.

John

But we do repot our trees regularly, don't we, and renew the soil.

And if someone uses organic fertilizers, there won't be any problem (unless you live in an area where there's shale fracking, in which case, lucky you if you can get the money, for the others, sas we say "you'll only have your eyes left to cry", for what can you do against such financial powers?).

Read this:

http://en.wikipedia.org/wiki/Terra_preta

Eco-friendly solutions are still possible. Tick tick tick... what countries f*ucked up the conference on climate because of their own interests? (funnily enough, they're the countries in which the death penalty is still legal: food for thought)

2009, Copenhagen: these artists took a stand, but "money is the root ofall evil", and the others are are the 1%, manipulating us to "put a band-aid on a wooden leg":

https://www.youtube.com/watch?v=aBTZOg6l6cA

By the way, using rain-water is OK if the air is not polluted. If it is, you will just concentrate pollutants, heavy metals and pesticides in you rain-tank after a period of drought.

interesting video for (social studies class ),
but i was hoping for more info on horticultural uses...

john, i will play devils advocate

any toxins absorbed by the charcoal would be from the surrounding substrate, so any toxins released back into the substrate would just be putting back whatever was there in the first place... correct ?

wait... as i re-read that, it occurred to me that i am working under the assumption that the charcoal was in a fairly clean environment from the time of manufacture to the time of being used as a substrate amendment...

now, if it were made in a tiny snow covered village as in the video, that may be the case...

but i have a feeling that charcoal manufactured in any industrialized city would be exposed to the same toxic stew we city dwellers dwell in...

i do have a bag of horticultural charcoal that i used to help my niece (the youngest AAC member at 10) build a terrarium...
i wonder if that is treated differently when manufactured... ?

What you mention as "manufactured" charcoal may be actived charcoal/carbon:

http://en.wikipedia.org/wiki/Activated_carbon

I also found this article on the use of activated charcoal in gardening:

http://healingtools.tripod.com/char_gard.html

Like other soil media, the chemical processes are complex to describe (and far beyond my knowledge to eplain), but even with what one would consider as "neutral", the exhanges of ions and how they recompose is in important factor for the nutritive qualities of the soil.

For instance chabazites are much more efficient than pumice, even if they look a bit alike: the way the nutrients are transformed to be absorbed by the plants differ.

good article in that second link... thanks.

(btw - when i wrote "manufactured" i just meant "made" bu what ever means that may be)

My only question is : To whom do I send the bill for those 28 minutes or so that was taken from me? Nothing horticultural that I saw. Did I miss something? I'll keep the charcoal in my smoker box!

Researching on my own yielded: stimulates mycorrhizal fungi and retains nutrients longer than regular soil. Add in some ability to retain carbon, and you've got.........Japanese use it so it must work? Yikes. And it took me less than a minute to find the info. Overkill.

Caveat - I have not looked at the links posted earlier in this thread.

That said, I have done some reading on the subject. What I've seen leads me to believe that charcoal's use isn't really as a means of removing toxins from water/soil. Rather, it seems like it should function to absorb fertilizer components which can then be released to the plant, i.e. it has a reasonably high cation exchange capacity (CEC). It also holds water.

The other benefit, compared to something like bark - the charcoal will not break down and turn to mush (at least, nowhere near as quickly as bark does).

One interesting note, the reading I have done indicates that the properties of charcoal (or "biochar" as it is often called) can vary considerably, depending on source wood and type of fire, etc.