Do any of you keep your trees in 100% pumice?

[Mike Corazzi]

If not, why not? The small (not "fine") pumice coaxes roots out of air layers.
It serves well as an ICU for ailing trees. (got one recovering in it now)
It doesn't break down like akadama.
I retains a good amount of moisture without being "wet."
It breathes well.

So, if it isn't a perfect "soil" why not?

 

[bonsaichile]

I do. Some of them at least. Usually, collected trees or trees that underwent a drastic root reduction

 

[AaronThomas]

I started growing two of my new Montezuma Cypress in pumice last year…. With weekly feeding during the growing season they did remarkably well.
After much discussion and feedback here on BN I decided to repot my other 3 MC in pumice as well.

 

[A. Gorilla]

Sorta. I will probably stick with that going forward.

I'm currently recycling and resifting an odd mix of perlite, growstone, pumice and lava.

Perlite breaks down somewhat and is too light and floaty for my liking....but its OK when sifted. Growstone would be perfect if it were smaller and rounder. Lava....not sure what that contributes. Weight maybe?

Just gonna stick with pumice.

 

[fredman]

I used to. Worked wonderful...except the azaleas didn't like 100% pumice. Mixed pine bark and shredded spagnum with the pumice and that went remarkably better.
I tried organic this year, but didn't work well for me. I'm going back to pumice/pine bark again this spring.

 

[RKatzin]

Just did my number 75 repot of this springs session, every one in just pumice. Sometimes I'll add some decomposed wood and sometimes some sphagnum moss, but I really can't see any difference between that and just pumice, and I've been looking at a lot of roots.

 

[TN_Jim]

Sorta. I will probably stick with that going forward.

I'm currently recycling and resifting an odd mix of perlite, growstone, pumice and lava.

Perlite breaks down somewhat and is too light and floaty for my liking....but its OK when sifted. Growstone would be perfect if it were smaller and rounder. Lava....not sure what that contributes. Weight maybe?

Just gonna stick with pumice.

Friend decades more experienced than me said difference between lava and pumice is both holding oxygen and cec potential, but pumice retains significantly water.

This distinction was interesting.


She uses 1:1:1 akadama pumice lava for most of mixes here I think

 

[TN_Jim]

Just did my number 75 repot of this springs session, every one in just pumice. Sometimes I'll add some decomposed wood and sometimes some sphagnum moss, but I really can't see any difference between that and just pumice, and I've been looking at a lot of roots.

Tainted pumice

 

[Johnathan]

I normally do 100% DE, last season I tried pumice and really liked it.

I was considering doing a 50/50 mix of DE and pumice for some JBPs. Would you that be just as good as 100% Pumice? Considering 100+ summers?

 

[Paradox]

I use a mix of pumice, lava and akadama.
Each has its own properties that work well as a soil component.
I have used pumice and lava only before I started adding in akadama.

I know some people vilify akadama because it breaks down.....its supposed to!
Harder akadama takes longer than softer akadama to break down.
So people that complain about akadama gettng mushy too fast are probably using akadama that is too soft.

 

[kale]

I do. Some of them at least. Usually, collected trees or trees that underwent a drastic root reduction

@bonsaichile fellow Coloradoan here! Do you get it locally? I would def use it if it was available at a hardware or landscape store but just cant find it.

 

[erich_raudebaugh]

Yes, some of my trees in development are in 100% pumice, usually with some sphagnum on top. Works great and I've been doing this for years. A couple growers here in Oregon, Randy Knight and Chris Kirk (Telperion Farms) do the same. Randy is the one who convinced me to try it.

 

[bonsaichile]

@bonsaichile fellow Coloradoan here! Do you get it locally? I would def use it if it was available at a hardware or landscape store but just cant find it.

I used to buy it at Paulino's. When they closed, last year, I went and bought several sacks of it. Damn developers. They are ruining my city!

 

[Potawatomi13]

YES. For Conifers. About 60-70% for broadleaves .

 

[AppleBonsai]

Been discussed before on BN, and I believe this is the last thread if it's helpful. https://www.bonsainut.com/threads/pumice-as-substrate.21350/ Personally, I adjust my substrate to the tree, my goals for the tree, the the container (size, shape, material, etc.) and finally the specific micro-climate I am planning. Over the years I've learned to adjust it and usually consists of APL for bonsai containers... and more organic components for growing material in nursery cans, but I am always experimenting and curious about your results with 100% pumice.

 

[vp999]

I would love to get my hand on some more affordable pumice, been buying them online and they cost just as much as akadama.

 

[RKatzin]

I would love to get my hand on some more affordable pumice, been buying them online and they cost just as much as akadama.

It's the shipping that costs. Even if I give you the pumice it costs $18 to ship 2gal in a medium flat rate USPS box.

 

[RKatzin]

I normally do 100% DE, last season I tried pumice and really liked it.

I was considering doing a 50/50 mix of DE and pumice for some JBPs. Would you that be just as good as 100% Pumice? Considering 100+ summers?

What is most important is size consistency. Particles of different sizes will separate over time, with the finer settling to the bottom. Forms an anaerobic mush and no roots grow in it. The best roots I've seen (and easiest to repot) are in pure pumice. The worst is pumice, turface, and potting soil. What a mess in the bottom of the container! Turface and pumice is a little better, best is just pumice..

 

[Maloghurst]

I use a lot of pumice. Usually 60%pumice 20%turface 20%lava because I haven’t found the good cheap lava yet.
At a Demonstration in January a professional stated that he uses 80% pumice and 20% manure for all his growing out material. I tried that and it was horrible for me held way too much water and it drained terribly. Maybe I’m missing some details of his method as how he sifts it.
I’m doing good with the mix I have.
@vp999 I fee like there has to be a bulk landscaping or trucking company within a hour from you where you can get cheap pumice but maybe I’m wrong.

 

[Bonsai Nut]

When I lived on the West Coast, I truly used garbage can loads of pumice. However, after years of experimenting, my best results were never with 100% pumice.

(1) First, piece size was important. I was careful to sift all my pumice, toss the fines, and keep the small pieces for smaller bonsai or small trees in development.
(2) Second, container was important. I had a lot of trees in development in pond baskets or Anderson flats that would dry out too quickly (in SoCal heat and low humidity) in 100% pumice. I started using low amounts of organics in those situations. If the tree was in a bonsai pot, I would often (but not always) mix in lava and acadama. Bonsai in ceramic pots did not dry out nearly as quickly.
(3) Third was the tree species and environment needs. The water in SoCal was extremely alkaline (pH 8.0+ out of the tap). Any trees that preferred acidic soil I found did much better if I added acidic organic matter to the mix (usually pine bark mini-nuggets). This was in addition to using acidic soil fertilizer.

Now that I live in North Carolina, soil needs are completely different. Our water is great but soft and acidic. People actually supplement their lawns here with lime to raise pH - the exact opposite of what we did in SoCal. Summers tend to be not as hot, and much more humid. I'll bet 100% might work great here... but you have to ship it in from the West and the cost is much higher.