Growing in un-screened cinder?

[Shima]

I have a student who refuses to buy or make screened cinder. He thinks his extensive collection will be fine in it. A very temperate climate here in Hawaii with lots of rain and no extremes. I'm in disbelief and considering giving him the boot. Sure, roots will fill the bottom of the container and the fines will clog the screen, but still. He stubbornly refuses to do any research and is stuck in his ways.

 

[PonderingSage:]

If given the option I wouldn’t waste my time on a student who refuses to learn. Your time will be better spent working with someone else.
(This is advice from a school teacher who doesn’t have the option to choose students)

 

[Deep Sea Diver]

Same here, 21 years teaching science….You know what, I’d just let the scenario play out. This is the only way the person is going to learn. Some folks just have to learn the hard way.

Just remember It doesn’t make you any less of a good teacher, it actually makes you a better one

cheers
DSD sends

 

[Shibui]

I've seen good bonsai successfully grown in all sorts of substrate.
I am assuming the student has been growing the trees successfully for some time in that soil mix if he is so determined to stay with it?
If it works for that person why change?

 

[Potawatomi13]

Honestly? Give the jerk the boot! AFAI concerned refusing to respect the trees deserves harsh rejection.