Anyone using charcoal in their soil mix ?

[Pixar]

Anyone using charcoal in their soil mix ?
Summertime here in NZ ( barbeque season was going to save some charcoal )

 

[rollwithak]

I do in my desert rose mix….. many plants will enjoy it…

 

[bluone23]

Added to a few trees could not see any difference.
Maybe sometime I will do a more scientific experiment like 10 trees with and 10 without.

 

[Potawatomi13]

Personally only use in drainage layer/mostly larger pots. Perhaps helps prevent sourness in wettest part of pot.

 

[It's Kev]

whenever i visit home and can actually have a barbeque, i chuck the leftover ash and burnt wood in the garden the next day, which i then work into the soil, i believe it's the same way that volcanic ash is fertile as heck
P.S. i have no facts that it works, it merely works coz i believe in it really hard, same like my spent coffee grounds

 

[KiwiPlantGuy]

Hi Fredman,
So I looked into this about a year ago, and it was advised on here that you can use up to 5% of your mix, could only be like a wood chip in some pots.
Maybe @Leo in N E Illinois has more information to agree or otherwise to my below statements.
The theory as I understand is the Charcoal (activated) is 100% Carbon which is the building blocks of all plant growth. But so is bark as it decomposes.
So my take is that if you subscribe to the inorganic mix which many do then Carbon is needed etc, while organic for obvious reasons has this type of Carbon already.
Charles.

 

[ABCarve]

I use it although not 5%…… maybe 2%. If you look at its CEC, it’s 200. Supposed to be a good home for microrysa. Don’t have any evidence, just makes me feel better.

 

[Dav4]

I'll toss a handful of horticultural grade charcoal into my mix when I remember to do it. It's really the only organic component I use for the more refined trees in pots other than the milled sphagnum moss spread on new re-pot's soil surface.

 

[JudyB]

I'll toss a handful of horticultural grade charcoal into my mix when I remember to do it. It's really the only organic component I use for the more refined trees in pots other than the milled sphagnum moss spread on new re-pot's soil surface.

Same here, especially in the Satsuki.

 

[Crazy Diamond]

If you use just raw charcoal you have to be conservative because at first it will take away nutrients and minerals from the soil until it saturates, but after it will release slowly the nutrients, some people saturate it first with nutrients and then use it in the mix

 

[penumbra]

whenever i visit home and can actually have a barbeque, i chuck the leftover ash and burnt wood in the garden the next day, which i then work into the soil, i believe it's the same way that volcanic ash is fertile as heck
P.S. i have no facts that it works, it merely works coz i believe in it really hard, same like my spent coffee grounds

This is not carbon.......... big difference.
I use some activated carbon (about 40 years or so) but more recently (a few years) I have been using bio-char.

 

[Michael P]

There is a great deal of scientific literature on biochar, but it is difficult to apply it to bonsai. I make my own, and use it at about 10% of my mix. It is extremely stable and does not decompose for decades, perhaps centuries, in soil. It has very high porosity and CEC. If you use too much it will raise the pH to undesirable levels.

 

[Yosemite Goat]

To add to the discussion;
And follow-up from the comment @Arnold :

I spoke with a soil scientist at NRCS, he said charcoal absorbs nutrients until saturated. When we discussed this in relation to bonsai he was not sure what would happen or if there would be any benefits. Esp since we often repot so often.

Over the years I have been placing a small portion in pots. I basically use the left-overs from our fire pit. I throw them in my soil mix at a 5-10% ratio.

Last year I repotted a tree in the same pot for 5yrs. There were fine roots around the charcoal pieces. Whether this is valid........ Further results need to be looked at.

 

[ChristianDGreat]

To add to the discussion;
And follow-up from the comment @Arnold :

I spoke with a soil scientist at NRCS, he said charcoal absorbs nutrients until saturated. When we discussed this in relation to bonsai he was not sure what would happen or if there would be any benefits. Esp since we often repot so often.

Over the years I have been placing a small portion in pots. I basically use the left-overs from our fire pit. I throw them in my soil mix at a 5-10% ratio.

Last year I repotted a tree in the same pot for 5yrs. There were fine roots around the charcoal pieces. Whether this is valid........ Further results need to be looked at.

In boons mix and i notice in Banzai blend (new akadama blend from japan, see Jonas site)
There's a little bit of charcoal in their mix. I think its not going to hurt if we try to add a little.

Thanks
Chris

 

[mrcasey]

I've experimented with a mix of 1/3 perlite, turface, and charcoal. I had some jbp, shimpaku junipers, and a Japanese maple in it. The maple died but I don't know if it had to do with the charcoal. The pines and junipers don't seem to care one way or the other. My reasoning was to have an organic component that wouldn't break down. My sample size is super small, but I'm not sure that the charcoal, even at 33%, makes much of a difference.

 

[yashu]

I throw in a bag of horticultural charcoal in my soil mix it ends up being maybe 5% at the end. I started adding it when “bio char” was the big thing. As others have noted, I don’t know if it helps but it certainly doesn’t hurt, it lasts quite a while, is free draining and the stuff I get (I think Hoffman’s but I’m not positive) has a good particle size.

 

[Paradox]

I also use horticultural charcoal.
Its made for use with plants
I would not use charcoal for the BBQ that is infused with lighter fluid or some other starter chemical ..........

 

[Pixar]

I will using charcoal straight from the bag ( we can buy charcoal from the supermarket )

 

[Paradox]

I will using charcoal straight from the bag ( we can buy charcoal from the supermarket )

I would just make sure it is pure charcoal, not one of the brands that pre-soaks it in lighter fluid to make it light easier.
I dont know what they have where you live, but here there are brands that are infused with lighter fluid

 

[Leo in N E Illinois]

Warning, in the USA, "charcoal briquettes" are not made from carbonized (partially burned) wood, "charcoal briquettes" are compressed coal dust from a coal mine. "Lump charcoal" is wood heated in low oxygen setting to create charcoal or bio-char and is indeed what we want. There's different degrees of heating. Activated charcoal has a greater number of chemical bonding sites due to careful exclusion of oxygen during the heating process.

I have always used charcoal, or bio-char in my orchid potting mixes, and in my bonsai mixes. Locally it has become a little difficult to source lately, but I still have some left from a 3 cu ft bag purchased a few years ago. It is best at less than 10% by volume of the total mix. Most "books and articles" recommend around 5% though I don't think exact amount matters much. It has great pore space, mycorrhizae seem to love it. It lasts a good 5 or more years, so it is good in mixes for trees that are not repotted often.

It is important to sift and sort particle size, so that your charcoal or bio-char are in the same particle size range as the rest of your media. Big lumps in a fine mix will cause drainage problems as will fine particles in a coarse mix.

Best way to improve any mix is with a set of sieves. Use your sieves. Discard fines, dump the lumps.