Soil component?

[mrt1]

I acquired about 100lbs of expanded slate aggregate. Nice 1/4 inch size. Anyone have any experience using this in your bonsai soil? Pros/cons? Thx for any replies.

 

[sorce]

Pics!

Sounds like something that could be mixed with something very retentive.

Slate or shale?

Sorce

 

[markyscott]

It's haydite. You can find a description of it here.

https://www.bonsainut.com/resources/inorganic-soil-reference-sheet.28/

 

[Stan Kengai]

Expanded slate is commercially sold as Permatil. It is different than expanded shale, know as haydite. It is a very good product similar to pumice, though not as porous and hence heavier. Permatil is, IMHO, sort of a cross between pumice and scoria. Pumice is a superior substrate, but expanded slate is a cheaper, viable alternative here on the east coast.

Be sure to rinse the product before using, as the dust can collect in the bottom of and clog pots.

 

[markyscott]

Expanded slate is commercially sold as Permatil. It is different than expanded shale, know as haydite. It is a very good product similar to pumice, though not as porous and hence heavier. Permatil is, IMHO, sort of a cross between pumice and scoria. Pumice is a superior substrate, but expanded slate is a cheaper, viable alternative here on the east coast.

Be sure to rinse the product before using, as the dust can collect in the bottom of and clog pots.

Thanks for the correction - I've heard of Permatil, but haven't run across it here. I'll check it out.

As I understand it, the product marketed as Haydite has a variety of starting materials including shale, slate and clay. But Permatil looks different at first glance - there may be a difference in how it is manufactured.

 

[mrt1]

Here's a pic of the aggregateView attachment 136107​

 

[mrt1]

 

[markyscott]

View attachment 136108

Thanks for the picture. A little low res, but does not look like haydite from what I could tell.

 

[bonsaidave]

Nice. I get mine from American Bonsai during their winter 20% off + free shipping for $100 orders. I use it as drainage layer and as part of my mix. Usually 10-20% depending on how much I have.

This guy has a couple sentences about it.
https://adamaskwhy.com/2017/01/27/i-feel-so-soiled/

 

[mrt1]

bonsaidave thx for the link. good stuff.

 

[bonsaidave]

There is more than enough info out there about soil components. That article is just short enough for my attention span .

 

[hemmy]

Interesting, I assumed expanded "slate" was just lazy terminology and it was all actually shale. But here's this from Stalite webpage:

"The raw material mined by Stalite is an argillite slate located in a geological area known as the Tillery Formation"

"Clays and shales are naturally softer, and less dense than slate. After processing in a rotary kiln, clays and shales have 24-hour absorptions ranging between 15% and 30% (compared to 6% for STALITE)"

http://www.stalite.com/stalite-production.php?cat=43

 

[hemmy]

Seems like there is LECA (lightweight expanded clay aggregate), expanded shale (haydite trade name) and expanded slate.

I've used expanded shale as a cheap filler in nursery containers. It was shale cooked in a rotary kiln and mined from quarries in KS and MO. It was about $6 for 60lbs bags and cheaper in bulk.

In the previous post, it sounds like ex. slate may have less porosity and all of these products appear to have a lot of closed porosity (the pore spaces are not all connected). Which makes water adsorption and availability for roots lower. In this regard, pumice and scoria may be better.

IMO, the differences are probably negligible when using it as a filler with organics in large containers. However, in an inorganic mix in shallow pots there may be some important differences.

 

[bonsaidave]

https://www.bonsainut.com/resources/inorganic-soil-reference-sheet.28/

I had not seen this PDF before. It contained some information I had not seen before about the Japanese soils. Good read.