Michael Hagedorn on 100% pumice soil

[leatherback]

Nice to see the discussion on soild move into a broader spectrum and not just the mantra that akadama is a must-have.

Pure pumice as substrate is well-known I would have said. As mentioned in this thread, the succulent world is one that uses pumice as a pure substrate. I used to collect and grow succulents in the 90-ies and that is what I used predominantly.
I am still convinced the balance of air-humidity provided by porous course media is the main factor. Most other variables fall within the care-takes range of effectiveness of people not focussing their life on growing optimally.

In a discussion with Rian Neil earlier this year, he indicated that from a biochemical perspective the high levels of manganese in Akadama is cause for reduces internode length. I did a little trial, and did find that under the same growing conditions, akadama does cause shorter internodes:

 

[BaKiBonsai]

...Pure pumice as substrate is well-known I would have said. As mentioned in this thread, the succulent world is one that uses pumice as a pure substrate...

In the botanical gardens in Leiden they use lava for the raised beds where the succulents and cacti are. I am also starting to see big raised beds in public spaces full of lava (or a thick top layer)

Rian Neil earlier this year, he indicated that from a biochemical perspective the high levels of manganese in Akadama is cause for reduces internode length.

Yes I like the video, I am wondering if the same can be achieved with pumice and manganese additive.

 

[leatherback]

Yes I like the video, I am wondering if the same can be achieved with pumice and manganese additive.

try it!

 

[BaKiBonsai]

try it!

I might the next repot loop, will start thinking about a good manganese additive. Currently experimenting with 100% molar clay, not a lot of growth so no real internode length to evaluate. The substrate stays quite wet and because there is not a lot of foliage I'm not even watering it daily. I do do a good watering when I pass them by.

Next will try some 100% pumice to compare. Then I can do one set with and one without manganese. Don't have a significant amount of seedlings so will see

 

[Deep Sea Diver]

In a discussion with Rian Neil earlier this year, he indicated that from a biochemical perspective the high levels of manganese in Akadama is cause for reduces internode length. I did a little trial, and did find that under the same growing conditions, akadama does cause shorter internodes:

Well done Jelle! Would love to see two more years, as that is when drastic differentiation might be plainly evident… or not, but these data are an excellent addition to the discussion.

Regarding future experiments with manganese.

Given manganese is the only culprit of many folks bonsai success, (which somehow seems simplistic… but pretty cool if true), there must be a subtle overage between the optimal amount for a tree and the amount contained in akadama.

Manganese, being a vital micronutrient, enhances photosynthesis, gives better resistance to disease, promotes root growth and development, and allows other micronutrients to be absorbed and transported around the plant better.

Yet the optimal level of this micronutrient is somewhat of a narrow band. In other words it doesn’t take a real lot more past the optimal point to reverse these effects. And it will take some time to show the visible symptoms i.e. yellow leaves - a form of chlorosis, dead spots and potentially wrinkled leaves.

Just a thought

Cheers
DSD sends

 

[BaKiBonsai]

I would have to consider the manganese difference between Akadama and pumice and then estimate how the uptake differs between the soils, taking washout into account..

I have some hawthorne seedlings which could result in a small scale setup

 

[Deep Sea Diver]

Great! Would love to see the results.

Cheers
DSD send

 

[leatherback]

Would love to see two more years

Sorry. I stopped at that point. I am TRYING to have fewer "little experiments" around the garden.
The stuff is filling every little gap and .. my bonsai section just looks crap as a result.

Really wish to return to 100-200 long-term keepers, and get rid of all little experiments and trials.

 

[BaKiBonsai]

Really wish to return to 100-200 long-term keepers, and get rid of all little experiments and trials.

Very understandable, and from my point of view you have contributed your share and more already. I learned a lot from the experiments though.

 

[Goodbrake]

is that source shareable?

I have found for perlite you either get cheap unsifted bags and the fine particules and dust that you are exposed to during sifting is BRUTAL. worse than any other medium IMO because of how light the material is all the fine particles get wafted through the air. I use an N95 mask and even still find myself coughing and irritated throat when sifting perlite.

This was just from home depot, but looks like it's out of stock now.

Viagrow 2 cu. ft. Perlite Coarse and Chunky Grade 59.8 Qt./56 L/15 Gal./7.26 Kg VPERCH1-2 - The Home Depot

Viagrow - 8 qt. Ft Perlite Coarse and Chunky Grade - use to aerate potting soil to promote a strong root system.

www.homedepot.com

It's not sifted, so I run the whole thing through sieves and get a few different sizes, all of them pretty usable, with even the fines being good for seedlings.