Anyone using charcoal in their soil mix ?

[mrcasey]

I source my charcoal from an outdoor fire pit. After sifting, I soak it in water a few times to try and get rid of some of the alkalinity. Don't know if the soaking helps/matters...

 

[Leo in N E Illinois]

I source my charcoal from an outdoor fire pit. After sifting, I soak it in water a few times to try and get rid of some of the alkalinity. Don't know if the soaking helps/matters...

Soaking is important for homemade charcoal as wood ash can be quite alkaline. Settlers, pioneer types used wood ash to make soap, as it was alkaline enough to saponify fatty acids in beef tallow. (Saponified fatty acids = Soap) If too much ash forms as you create charcoal you will have alkalinity issues. Excluding oxygen during the heating gives better conversion to charcoal with less ash forming.

Commercial horticulture grade charcoal the process is more controlled, and as received should be neutral. No soaking needed. This is why I buy it rather than hassle with making it.

 

[Gabler]

When I was studying archaeology, charcoal was an important topic of discussion, since carbonized organic matter lasts effectively forever, but raw organic matter decomposes quickly, and it’s lost to the archaeological record. As an example, my professor used to pass around a perfectly-preserved loaf of bread, turned into a deep black charcoal. I wish I had a picture to post.

Anyway, insofar as it affects bonsai substrate, “biochar” charcoal effectively won’t ever break down chemically in the soil, but it will break down mechanically. It will gradually lose its structural integrity, eventually turning to dust. I believe that’s likely why @Leo in N E Illinois indicated a five-year timespan for using it. It’s not much different from Akadama in that sense. That said, I don’t know whether roots can thrive in broken-down charcoal the same way they can thrive in broken-down Akadama. The properties might not be the same.

 

[Leo in N E Illinois]

When I was studying archaeology, charcoal was an important topic of discussion, since carbonized organic matter lasts effectively forever, but raw organic matter decomposes quickly, and it’s lost to the archaeological record. As an example, my professor used to pass around a perfectly-preserved loaf of bread, turned into a deep black charcoal. I wish I had a picture to post.

Anyway, insofar as it affects bonsai substrate, “biochar” charcoal effectively won’t ever break down chemically in the soil, but it will break down mechanically. It will gradually lose its structural integrity, eventually turning to dust. I believe that’s likely why @Leo in N E Illinois indicated a five-year timespan for using it. It’s not much different from Akadama in that sense. That said, I don’t know whether roots can thrive in broken-down charcoal the same way they can thrive in broken-down Akadama. The properties might not be the same.

Properties of charcoal are not the same as akadama, but both are useful media components because they both have a 'long useful cycle.