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

[TN_Jim]

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?

I started supplementing trees with pumice that needed more drainage than provided by DE alone such as Eastern Hop Hornbeam. I do not have pines, but one difference I have noticed is less susceptibility to fungal leaf issues -I also use pine bark.

 

[Pads]

Various collected olives were all poted in 100% pumice (2-4mm) and are all doing great. Here in southern Greece we do not generally use this recipe except for collected trees (unless you can water your plants 3-4 times a day during the summer). Usually pumice is mixed with various percentages of coco peat to retain moisture.

 

[sorce]

I'd LOVE to see these trees defined as growing "great" in Pure pumice.

Of course, to be useful, there will have to be progression photos, or similar trees in other soil etc.

2ft candles would be sufficient.

What I doubt is the definition of "great", not your honesty.

It must be just another something that doesn't work here.

@Bonsai Nut they're going to start calling you Mr. Calawnfornia.

Sorce

 

[Mike Corazzi]

Various collected olives were all poted in 100% pumice (2-4mm) and are all doing great. Here in southern Greece we do not generally use this recipe except for collected trees (unless you can water your plants 3-4 times a day during the summer). Usually pumice is mixed with various percentages of coco peat to retain moisture.

And pumice with coco peat sounds like it would approximate pumice with some roots IN it.
What could be more perfect?
Discussing hard and not so hard akadama puzzles me. Why in the world use ANYTHING that eventually degrades?
I wish I had posted this thread before repotting time.

 

[bwaynef]

I'd LOVE to see these trees defined as growing "great" in Pure pumice.

Of course, to be useful, there will have to be progression photos, or similar trees in other soil etc.

2ft candles would be sufficient.

What I doubt is the definition of "great", not your honesty.

It must be just another something that doesn't work here.

@Bonsai Nut they're going to start calling you Mr. Calawnfornia.

Sorce

I highly recommend (what I've read so far of ) @Crataegus!' (I assume that's Michael Hagedorn) _Bonsai Heresy_. His bit on soil mentions that maybe we should be looking at soils that support a rootball that can go a while w/o being repotted. He also mentions that there are soils that support more vigorous growth, like those 2 foot candles you mention. He details why that may not be the goal of mature trees, ...and goes on to point out why some desired qualities in a soil change once you get to refinement.

(I hope I've done what I've read justice.)

 

[Mike Corazzi]

No more repotting could destroy the tranquilizer industry!

 

[Pads]

I'd LOVE to see these trees defined as growing "great" in Pure pumice.

Of course, to be useful, there will have to be progression photos, or similar trees in other soil etc.

2ft candles would be sufficient.

What I doubt is the definition of "great", not your honesty.

It must be just another something that doesn't work here.

@Bonsai Nut they're going to start calling you Mr. Calawnfornia.

Sorce

You are right. The truth is I have never used any other inorganic (eg acadama) so I have no basis for comparison.

 

[Shima]

I'm going back to pumice/pine bark again this spring

You don't consider pine bark organic?

 

[AaronThomas]

I believe this is the last thread

Lol that was started in 2015....
Been a few since

 

[fredman]

You don't consider pine bark organic?

Yep, I do...what gave you the idea I don't?

 

[Paul G]

@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.

try a cannabis supply store.

 

[Igor. T. Ljubek]

Hmm, 100% pumice with no organic? I would add at least 15% (more likely 20% to 25%) pine bark or sphagnum moss. What are the benefits of 100% pumice or any other 100% inorganic substrate?

 

[sorce]

truth

I didn't mean you alone, though it was your "great" that I was thinking of.

It's just that, most people don't have "actually great" to compare it to.

Hell, the amazingness of an old tree collected from the mountain, and surviving alone, is "great" to near any human.
This doesn't mean they actually do "great".

Newbs compare "great" to dead Walmart trees.

Experienced folks with slow growing trees compare great to that slow Growth.

We all have our reasons to consider growth great.
It's the admission that it isn't that's tough.

Sorce

 

[Mike Corazzi]

Hmm, 100% pumice with no organic? I would add at least 15% (more likely 20% to 25%) pine bark or sphagnum moss. What are the benefits of 100% pumice or any other 100% inorganic substrate?

Resistance to breakdown. Less frequent repots.

 

[Leo in N E Illinois]

I have used 100% pumice, and it has worked fine. Pumice is the single best component for a bonsai media.

The issue with akadama - I can not read Japanese, you never know whether the new bag is the "good stuff" or the soft crap. I have a bag right now that in the unopened bag, stored outside, it turned to soft mush over 1 winter. That is it, I'm not buying any more of that crap. My "local" vendors of Akadama can't read Japanese either. They didn't know what grade they were getting. It is just unreliable in the USA supply chain. And expensive.

 

[Yugen]

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

I head that pumice has near zero or zero CEC

 

[Yugen]

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.

I see how finer granules would be good for smaller trees, but 1/8-1/16 ( still small, no?) be good for established trees? I thought that the granule grain size and root size were matched, in that we desire small roots and that is facilitated by a finer soil matrix?

 

[Yugen]

I deal with mostly yamadori. I use pure pumice with great results. Works equally well with my field grown. My hemlock in particular has tons of roots and mycelium. Pumice makes it so I practically can't over water and yet allows for available water for roots all day long. I'd like to have akadama or a Boon's mix ($$$..) as I've seen photos to attest to the difference in root growth.
I'd say the draw backs are:
1) I've heard ( I can't verify) that pumice has low to zero CEC which can make fertilizing complicated.
2) It requires sifting which is laborious, time consuming, is bad if you breathe in the dust and leads to throwing away a lot product

For me, commercial barn/garden stores have large bags of pumice in different sizes. I can't imagine shipping this stuff and paying for postage.

I wonder what I'm missing by not having lava rock

 

[penumbra]

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.

I understand this having been in horticulture most of my 70 years, But if you choose the materials well and repot when you need to, it is not a problem.

 

[fredman]

I've heard ( I can't verify) that pumice has low to zero CEC which can make fertilizing complicated.

Quick search and I found this.

CEC can be bettered then by adding sphagnum moss or/and pine bark.