Kiryu Soil??

[Paradox]

Hi all,

I am starting to see the term "Kiryu soil" being used more and more recently.
I am not familiar with this soil and I dont recall seeing it anywhere before.

Can someone explain what it is and where it comes from, where it can be ordered from?

Thanks in advance

 

[Ruddigger]

I think it’s basically a type of Japanese pumice.

 

[Nybonsai12]

it’s Japanese river sand, I believe house of bonsai sells it. I had some a few years back from them through eBay

 

[TomB]

Very different composition to regular ‘sand’ though - it’s porous. It’s basically equivalent to lava.

 

[Paradox]

ok so if I already have lava and/or pumice I can use those instead.
I already stock 4-5 types of soil components, I really dont want to start with another one

 

[Deleted member 32750]

Kiyru is most similar to pumice though it is river sand. I use aoki blend which has kiyru in it and it seems to me that it is less water retentive than Pumice, making it a suitable soil component for conifers.

 

[Paradox]

Kiyru is most similar to pumice though it is river sand. I use aoki blend which has kiyru in it and it seems to me that it is less water retentive than Pumice, making it a suitable soil component for conifers.

Ive used lava, pumice, akadama mixed in a 1:1:1 ratio for pines and junipers for years with no issues at all.
So this just again reinforces to me that I dont need to stock and store yet another soil component

 

[Deleted member 32750]

Ive used lava, pumice, akadama mixed in a 1:1:1 ratio for pines and junipers for years with no issues at all.
So this just again reinforces to me that I dont need to stock and store yet another soil component

I 100% agree. If you have Pumice just use that it’s practically the same

 

[bluesky]

I'm late to the thread here, for which I apologize.
I have used both kiryu and european pumice for some time now, mixed with akadama and whatever else I have handy. I can tell you that kiryu and pumice are very similar in texture, weight, water retention and drainage properties. ç

But Kiryu has one advantage, it changes colour drastically when wet, from off-white to orange-brown. This makes it an excellent top dressing. Last year I was using pure kiryu as top dressing, and it dries too quickly in the harsh spanish sun - same as pumice. This year I think I now have the ideal top dressing, kiryu and akadama 50/50 mix, small granules, about 2-3mm (1/10"). The akadama component retains water longer, and changes colour when wet, so is also good as top dressing. Except the small particles of akadama start to break down on the surface after 9 months of watering. The kiryu holds structure, so the 50/50 mix is great.

And for completeness: in the main soil I use larger kiryu/pumice/akadama particles - around 4-5mm (1/6 - 1/5") . As kiryu is about double the price of pumice, I buy pumice for this. + some lava for extra weight in shallow pots or pine bark for extra retention in deeper pots.