Soil mix decision

[Leo in N E Illinois]

There are a fistful of VERY long extinct volcanoes in the state, but to my knowledge pumice or the like is fairly rare.
However, granite is the very stuff the mountains are made of, and quartzite deposits are common. Granite gravel with some light soil, compost or mulch mixed in for water retention is where I've had the best luck so far.

At out new home, the irrigation ditch routinely needs cleared of sediment, which is usually in the form of a very fine sand. Except for it being virtually unusably fine, it's almost perfect lome. Full of nutrient rich silt, and just soft enough for roots to run through. I'm hoping to find a good way to cut it for better aeration. Perlite isn't doing the job at all.
The old landscaping here also includes allot of large red lava rock that I need to find time to break down to 1/4 inch or smaller.

The issue with loams, composts, silts and sands is particle size. Dry all the materials out, then sift them. Anything fine enough to go through window screen (the size used to exclude mosquitos & flies) should be thrown out. The fine silt, even though it is soft, it will clog up the air voids in your potting media. The goal is "chunky stuff", particles 1/8th to 1/4 inch for pots under 6 inches diameter. And 3/16 go 7/16ths for medium size pots, under 16 inches diameter.

Sand is bad. One component which is good for training pots is Perlite. Its not that expensive to buy, all the marijuana grow shops have it for the pot farmers. Chemically it is nearly identical to pumice, it is just a bit lighter weight than pumice which makes it hard to use in a shallow bonsai pot. But it is great in Training pots and pots more than 2 inches in height. Put a layer of moss on top, long fiber sphagnum or living moss you collect, to hold the perlite in the pot so it doesn't splash out when watering.

As I said earlier, composted leaves are a good addition, sift to get rid of fines, use what stays on top of the window screen.

Horticultural charcoal, or home made bio-char are excellent additions to a potting mix. Google "how to make bio-char" and you will get a huge number of articles to look at. Remember you want to end up with particles 1/8th inch to maybe 3/8ths inch. You will have to figure out how to get that size range out of your biochar.

Charcoal briquettes for the BBQ grill are NOT charcoal, they are coal dust glued into briquettes. Natural hardwood charcoal is the same as horticultural charcoal, the only issue is breaking up the pieces to the right size for bonsai use.

DO you have a wood chipper?

Silt, sand and fine loam and clay are all too small a particle to be useful.

 

[Leo in N E Illinois]

If you have a NAPA auto parts store, NAPA Part Number 8822 is an oil dry that is made of 100% crushed diatomaceous earth. My issue for not liking it as a potting media is that it is too small a particle. More than half a bag will fall through a window screen. I throw that portion out. The excess fines make it as expensive as the perlite from the marijuana grow shops. At least the perlite I can get in several different sizes, and don't have to throw half of it out.

I realize you are on a budget. So buying anything may be prohibitive, but if you do find the money. Just saying.

If I only bought one thing, it would be 40 pounds of pumice. You can grow excellent bonsai in nothing but pure pumice. And just about any home made mix would be improved by the addition of pumice.

 

[ShadyStump]

All this I've learned already through research or painful experience. I Iuess I have issues with not being able to find a use for such rich loam.

We buy a 25 pound bag of perlite every year for potting mix for our vegetable starts. (Talk to my wife about marijuana. Never been my thing.) We've started two separate compost bins, one brown matter only, the other a mix including manure from the chicken coop.

We haven't built a new outdoor fire pit yet since we moved, but it will happen by summer. I've heard awful things about the CEC of charcoal, though I've yet to have problems with it myself.

And yes, there's an 80s vintage home scale wood chipper left from the previous home owners we're fixing up this year.

All I need now is time.
There's always a catch.

 

[leatherback]

There's always a catch.

Success comes to those who are able to release catches!

 

[Starfox]

Just bought a bag of brand name kitten litter, but in their budget line, which states it is 100% Attapulgiet. This is a mineral often used in potting mixed to increase aeration, absorption and nutrient retention. Thought it might be good. 30 liters for 8 euro. 7 1/2 gallon.

View attachment 360284

I use the 'Pink' bag of that brand which is the Danish Moler, it's served me well but getting harder to find. I think it's another perk of Brexit. Looks like I will have to find another source of it, I know it's used in various ways and licensed under different names but the sanicat pink is a really good particle size.

Thankfully I have a bit leftover and it's reusable to get me through this season. I can take a close up of the particles with a scale later on if any one is interested.

 

[leatherback]

Just bought a bag of brand name kitten litter, but in their budget line, which states it is 100% Attapulgiet. This is a mineral often used in potting mixed to increase aeration, absorption and nutrient retention. Thought it might be good. 30 liters for 8 euro. 7 1/2 gallon.

View attachment 360284

OK, 24h water test showed: This is money wasted. Will make my neighbour with cats happy.

 

[leatherback]

the 'Pink' bag

Thank You!
.. off to the store soon!
Do you have a picture or the name?

 

[Starfox]

Thank You!
.. off to the store soon!
Do you have a picture or the name?

It's this one.
But not the one with aloe and not the one that says rainbow or oriente.
I have also seen it marketed as Sophisticat Pink and possibly Kitty Friend.
Like I said though I can't find it locally at the moment so if you find a EU source that will deliver then I'm all ears.

 

[leatherback]

nope, sold out everywehere

 

[Starfox]

Yep, I think that brand was only available to the EU marketplace via the UK, I always ordered via amazon.es but it always came from the UK.
Maybe the Irish have it, at some point I´ll scour some IE sites but I reckon it has to be available locally as some product somewhere. I know it goes by Terramol and Skamol and pretty sure I have seen it scattered after car accidents on the road as an absorbant here so maybe I´m missing something obvious.

 

[shinmai]

If you have a NAPA auto parts store, NAPA Part Number 8822 is an oil dry that is made of 100% crushed diatomaceous earth. My issue for not liking it as a potting media is that it is too small a particle. More than half a bag will fall through a window screen. I throw that portion out. The excess fines make it as expensive as the perlite from the marijuana grow shops. At least the perlite I can get in several different sizes, and don't have to throw half of it out.

I realize you are on a budget. So buying anything may be prohibitive, but if you do find the money. Just saying.

If I only bought one thing, it would be 40 pounds of pumice. You can grow excellent bonsai in nothing but pure pumice. And just about any home made mix would be improved by the addition of pumice.

When I was experimenting with 8822, I found a solution to the particle size problem. When I put it through my fine sieve, I had the same experience—fully 50% fell through as fines, effectively doubling the price per pound. I re-bagged the fines, and gave the bag to my father in law, whose ancient Camry dripped oil on his garage floor—thus returning the dust to its intended purpose.
Now I’ve evolved to using straight kanuma for my azaleas, and aoki mix for everything else. [I do not do conifers, which as the Wizard said, is a horse of a different color.]

 

[Mycin]

8822 is great because it's likely available to you within a 30 minute round trip. Beyond that, I've found it to be more headache than it's worth. But I freely admit that may be due to user error.

If you have a bonsai shop within driving distance, their mix is probably the cheapest/easiest option around. Soil is heavy and shipping costs make ordering a costly proposition, even if you blend it yourself. The local shop here, BCBonsai, sells a gallon of good medium for $8 if i recall correctly. Mixing soil on my little balcony was such a hassle that I'm heavily leaning towards this route while I'm trapped in condo hell

 

[Underdog]

Coincidently, I just bought a Bag of NAPA 8822 yesterday. I've been using it for 6yrs now with good results. This bag sifted extremely well and had almost no fines. Going back tomorrow to buy another off the same pallet.
I got about 70% over 1/8" and over half of the remainder caught in my Spaghetti strainer. I usually save the fines for the shop use but had almost nothing left.

This is not the norm, Maybe buy 2 more bags tomorrow...
I reuse this stuff for years too. Only time I had mush problem was before I had a good way to sift.

 

[Warlock]

Safe-t-sorb. Oil-dry, Turface and NAPA 8822 all seems very fine.. Didn't like that. Probably gonna give it to my mechanic shop.

The pumice and Expanded Shale I found was all consistent size. No fines sifted out at 1/4".. Nothing over 1/2"..

 

[Underdog]

Safe-t-sorb

Sucked along with opti-sorb. Both turned to mush.

 

[BuckeyeOne]

Lava, Pumice and Bark chips

My go to!
Can't get akadama, but may have to bite the bullet!

 

[BuckeyeOne]

Could someone here please share specific brands of kitty litter that would be suitable?

Not worth it. Spend a little more or good components.
You'll thank me later. I know.

 

[Leo in N E Illinois]

Not worth it. Spend a little more or good components.
You'll thank me later. I know.

I'm being sympathetic to the OP's original description of their situation. I've been doing bonsai for many years, and have been reasonably serious about it for the last 20 years. Started over a few times for various reasons. I've used an incredible array of components for media. There are "cheaper alternatives" than the fancy imported Japanese dirt. They work. But I have had my best results with "the good stuff".

So I do invest in Kanuma for my azalea, and pumice, lava and akadama. This is my current "go to" set of components.

But at one time or another, everything I have suggested above, I had used at one time or another, and had at least pasable results.

 

[just.wing.it]

I'm being sympathetic to the OP's original description of their situation. I've been doing bonsai for many years, and have been reasonably serious about it for the last 20 years. Started over a few times for various reasons. I've used an incredible array of components for media. There are "cheaper alternatives" than the fancy imported Japanese dirt. They work. But I have had my best results with "the good stuff".

So I do invest in Kanuma for my azalea, and pumice, lava and akadama. This is my current "go to" set of components.

But at one time or another, everything I have suggested above, I had used at one time or another, and had at least pasable results.

Hey Leo!
Do you use 100% Kanuma for azalea?

 

[Rivka]

If I only bought one thing, it would be 40 pounds of pumice. You can grow excellent bonsai in nothing but pure pumice. And just about any home made mix would be improved by the addition of pumice.

I got a great deal on 80lbs of pumice last year and have been cutting it into everything else i work with. Seems to be a good laid back cheep filler that makes all the more costly media stretch farther.