Pumice users

[Scott Roxburgh]

This link may be of interest too:

http://peterteabonsai.wordpress.com/201 ... g-a-beast/

[Biofusion]

So Scott your saying a size of 4-6mm for most larger trees, 2-3mm for shohin, and 1mm for cuttings?

[GavinG]

I've used 1-4mm pumice, either 50/50 with native potting mix, or 80% with 20% coco peat, and haven't noticed a lot of difference between them. If 1-4mm pumice drains very freely, I can't quite see the point of using larger grit - smaller particles hold more water on their greater surface area, at least theoretically. I haven't watered more than once a day through summer, not even the littlies (although they were shaded.) The two drawbacks with pumice are that it's white (same problem with Mt Sylvia diatomite) and that trees are unstable in it, as with all of the high-grit mixes - trees need to be wired in. Pumice and diatomite both absorb water with normal watering, zeolite less so.

Gavin

[Scott Roxburgh]

First note is that I use automatic overhead watering, and in FULL sun all day.

So the sieve mesh size is 2mm, 4mm & 7mm

7mm is for drainage, I've tried it on Black pine but can't comment of its appropriateness.
4-6mm is for conifers, none of my deciduous are large enough.
2-3mm is for deciduous, and I suppose shohin conifers, but none of my small conifers are in small enough pots to warrant it.

I do not use any (what bonsai people term) organic material such as potting mix, peat or bark. I have found that the 1mm is too fine and impedes drainage. I have also experienced it caking up and forming a solid barrier that water does not penetrate after a year.

The white colour has never been a problem for me, as it darkens with the Akadama, and it should be covered in moss when you show trees. IMO all trees should be tied into the pot whether you use high grit or not.

[Biofusion]

Hmmm, might have do some trials here.

I think sieve out the big stuff >6mm and small stuff <2mm and use the in between of 2-6mm, and if it doesn't get good results try narrowing the mix to 2-4mm and 4-6mm.

From what I can see, a lot of people are getting results with a large variance of particle size from 2-6. But I can definitely see how a more uniform particle size may possibly yield better results. But only a trial would tell I suppose.

Sieving of course I think would be essential for smaller pots.

This is interesting guys thanks for all the feedback.

[Stewart_Toowoomba]

where do you get your pumice from everyone and does it some in different sizes?

Prices??

Stew

[Rolf]

where do you get your pumice from everyone and does it some in different sizes?

Prices??

Stew

Hi Stew,

You should get your pumice here http://www.australianperlite.com/pumice/horticulture/or from local nurseries if available.

Cheers
Rolf

[Biofusion]

Is everyone using an organic based fertiliser with their pumice mixes? Or inorganic? I would be interested to hear some thoughts, especially people who may have used both, to see how well the pumice holds onto organic particles in its structure.

[Scott Roxburgh]

I use a 50/50 blend of cottonseed meal and blood and bone formed as cakes, either in teabags or not.

I also use fish emulsion, and miracle-gro alternating weekly.

A bit of osmocote mixed into the soil doesn't go astray either.

[cre8ivbonsai]

Went and saw an excellent demonstration by Mauro Stemberger last night, and interestingly he plants his Yamadori straight into Pumice and or Perlite, in a position that gets a lot of water to the roots, but in full sun. He mostly collects varieties of pines. Once the are potted up as 'bonsai' he uses 100% Akadama. But as he stated, Italy is different to Australia, and many factors come into play when choosing a growing medium, mainly; species of tree; climate; and availability of supplies.

[Damian Bee]

where do you get your pumice from everyone and does it some in different sizes?

Prices??

Stew

Hi Stew,

You should get your pumice here http://www.australianperlite.com/pumice/horticulture/or from local nurseries if available.

Cheers
Rolf

If you are in Melbourne. http://www.ology.net.au/#!bonsai-soils/c1n0f

[Damian Bee]

I have been using Seasol and its buddy Powerfeed as well as Seamungus and slow release.
I would hazard a guess that one of the few issues (which is really a non issue) is that organic fertilisers may speed up the growth of green fuzz on the surface layer of pumice but its going to take a while. It happens with Perlite much quicker and also with diatomite.
If you are using pelletised ferts like seamungus or dynamic lifter, the fines may clog up or inhibit air and water penetration but if you are repotting regularly its not a problem
You can also re-use your pumice making it very good value, just be aware that if you had a plant that died from a disease while in the pumice, you may want to consider some control measures.

[Rolf]

Is everyone using an organic based fertiliser with their pumice mixes? Or inorganic? I would be interested to hear some thoughts, especially people who may have used both, to see how well the pumice holds onto organic particles in its structure.

Hi Biofusion,

I'm using mainly Powerfeed Commercial(Seasol) and Thrive Soluble(Yates) for all my Bonsai every two weeks in growing season. I'm collecting the fertiliser which usually runs straight through the mix of pumice/akadama and use it for my stock plants in commercial potting mix.
Works a treat and is less wastage.

Cheers
Rolf

[Andrew F]

Went and saw an excellent demonstration by Mauro Stemberger last night, and interestingly he plants his Yamadori straight into Pumice and or Perlite, in a position that gets a lot of water to the roots, but in full sun.

Is that for water retention or to circulate air to the roots better?

[Goff]

Went and saw an excellent demonstration by Mauro Stemberger last night, and interestingly he plants his Yamadori straight into Pumice and or Perlite, in a position that gets a lot of water to the roots, but in full sun. He mostly collects varieties of pines. Once the are potted up as 'bonsai' he uses 100% Akadama. But as he stated, Italy is different to Australia, and many factors come into play when choosing a growing medium, mainly; species of tree; climate; and availability of supplies.

I have been using 100% perlite on collected olives for the past year and it works really well and much easier to move around larger trees