Clay king/ Soil questions


Jonas, I have been reading and re reading your blog posts about soil types and again found your posts super helpful. I have been learning as much as i can about the different soil types.

I know the ready mix you sell is 70% clay king and 30% pumice. I understand that clay king is akadama, kanuma, and kiryu. I also understand that kanuma and kiryu are named after the areas they are harvested in Japan.

What exactly is kanuma and kiryu?
What is the average % of each in clay king?

With your ready mix would adding lava rock to it be pointless since it already has pumice to make it dryer?


(Jonas Dupuich) #2

The best description I know of about kanuma and kiryu, among other substrate used for bonsai, is from Dr. Scott Barboza on the Houston Bonsai Society Website:

It’s hard to say the percentages of the non-akadama components of Clay King as they can change from batch to batch. I’ve seen kiryu (aka “river sand”), kanuma, lava and hyuga (pumice). The percentage of akadama stays at roughly 60% for the conifer mix (black bags) and 80% for the deciduous mix (red bags).

A 30% pumice 70% Clay King mix is about 42% akadama. Adding lava would be a good way to further to reduce the total percentage of akadama in the mix.

(Les Lonsdale) #3

Thanks for the link to soil substrates! This is a GREAT article!


Is crushed granite the same thing as decomposed granite?

(Jonas Dupuich) #5

The rock in the photo looks different but it could just be another kind of granite. The main characteristic is close to zero porosity.