AusBonsai

Hello people,

Who here uses pumice as an ingredient in their soil mixes?

I am particularly looking to find out in what proportions it is used, with what materials, and how heavily you water?

For instance, I have heard some people say that pumice, because it floats, will separate on the top of the soil over time.

I am wondering if this is indeed the case, if pumice users have had to change their watering techniques, or what they may have done to overcome this problem.

This I know, is going to depend in what ratios are used and what other ingredients are used with it, hence the first part of my question.

Do not use it myself, but will get some to try in my mix and will do so up to about 20-25%
Unless you flood your pots or submerge them, it doubt the floatiness of it will matter.

Ken

I've been using it for the last 6 months or so. Haven't found any issues with it coming to the surface. I'm using it at around 20% of the mix. Nice stuff to work with, once it's been cleaned.

I have been using and trialing pumice in various sizes for around 2 years now in various ratios from 1-100% and have found no issues with buoyancy.
It's great stuff. As was mentioned, unless you are submerging the whole rootball there is no issue. Also, I have left unused mix out in a bucket which has filled up with rainwater and the pine nuggets are the particles floating.
As far as watering goes, depending on your mix, there is no need to change your watering habits, (unless you are blasting your pots with a heavy stream or jet).

Anyone using it as the main portion of their mix for drainage, perhaps up to 50%

All responses have been great so far, thanks

my mix is 30% pummice, 30% blue metal, 30% organic, 10% couse river sand.

Never had a problem with seperation and found the mix to work great. i grade all my materials when i get them and use the same grade pummice as blue metal.

It gets a bit pricy if you are using it as a drainage layer, I use 10-20mm gravels or coarse sands for that.
Pumice has great water absorption and air filled porosity properties, best used in your mix not under it

Equal parts pumice zeolite and kleensorb with some moss thrown in for good measure, as Walter pall attests to here http://walterpallbonsaiarticles.blogspo ... glish.html modern substrates and well fed and watered trees are the way of the future.
Get on board I say

H

And what is everyone sieving their pumice too, and for that matter their other ingredients that are granular.

I see most particles being around the 2-8mm size in most of the commercially offered substrates.

The shohin sizes preferring around the 2-3mm size and the larger trees between 4-8.

I can see sieving being important for smaller trees, but for larger trees would anything ranging from 2-8mm be fine straight out of the bag?

Any advantages to sieving for larger trees?

The majority of my trees are in colanders or similar open style baskets / pots, I don't sift anything I just avoid using the dust at the bottom of the bags, I don't have enough time or patience to sieve. Perhaps when they go into 'final' pots - but probably not.

Hi there,

I'm using pumice 50% with 50% akadama (for 7 years) mainly for my JBP but also tried successfully with chinese elms and junipers. Size is 4mm with same size akadama. I did get the pumice from Ausperl in New Zealand, before they opened a company in Australia. The JBP love the substrate and developing very healthy mycorrhizae also the drainage is exquisite.

Cheers
Rolf

Haydenmc wrote:The majority of my trees are in colanders or similar open style baskets / pots, I don't sift anything I just avoid using the dust at the bottom of the bags, I don't have enough time or patience to sieve. Perhaps when they go into 'final' pots - but probably not.

Same for me.
Everything from 2 - 8 mm in the pot. I sieve for Mame or small shohin pots tho.

Ken

rolfster wrote:Hi there,

I'm using pumice 50% with 50% akadama (for 7 years) mainly for my JBP but also tried successfully with chinese elms and junipers. Size is 4mm with same size akadama. I did get the pumice from Ausperl in New Zealand, before they opened a company in Australia. The JBP love the substrate and developing very healthy mycorrhizae also the drainage is exquisite.

Cheers
Rolf

Hi Rolf,
Have you tried 100% pumice for your pines?

Damian Bee wrote:

rolfster wrote:Hi there,

I'm using pumice 50% with 50% akadama (for 7 years) mainly for my JBP but also tried successfully with chinese elms and junipers. Size is 4mm with same size akadama. I did get the pumice from Ausperl in New Zealand, before they opened a company in Australia. The JBP love the substrate and developing very healthy mycorrhizae also the drainage is exquisite.

Cheers
Rolf

Hi Rolf,
Have you tried 100% pumice for your pines?

Hi Damian,

No I have not. I always mix akadama in my mix because Perth is very dry even in winter. Have you???

I know that Wolfgang Putz and Walter Pall have used only pumice, but they have much more rain in Austria/Europe in general then what we have here in WA.

Cheers
Rolf

I've been using pumice for three or fours years I can't remember. Prior to that I was using diatomite.

I have tried Pumice at 100% on JBP and Banksia Integrafolia. Both grew fine but required more water than I wanted to give them (my usual watering is watering system on 5mins in morning then 2mins at 12pm, and 2 at 4pm in summer)

It is great for establishing fine root growth but IMO adding another element that buffers the Pumice is best, I use Akadama a the same particle size as the pumice.

I buy 1-7mm pumice sieve the 7mm out for drainage/larger trees, then the 4-6mm, then the 2mm+ and use the washed 1mm for cuttings (it is basically sand). Large particles for evergreens, smaller for deciduous.

Prior to having scoria/lava in a workable size <10mm, I used Pumice/Akadama 50/50 on every tree type except Satsuki (Kanuma).

I have only had a problem with buoyancy on two trees this year. The fine root growth is impeding drainage as they should have been repotted last year. These trees have been in the mix for three years.

Along with wiring trees in pots, I believe that sieving & grading the medium is one of the most important aspects of maintaining trees to an extremely healthy state. If you can moderate the variation in particle size, watering habits, fertilser, new root formation, year in year out, the trees become a lot more predictable and easier to get the desired form.