I personally never used sphagnum moss to cover the pot filled with either akadama/kanuma (satsuma). I went to a course and they say that bonsai grow much better with it. Just to be careful to water when it is completely dry. I well aware that in Japan it is used mainly after repotting. What do you think about it?
thank you for your answer

I don't see how it makes a difference in a positive way. It makes the watering harder. It only makes decorative purpose. It looks better and realistic when it comes to bonsai shows and competition. Besides that. I would never use it.

i agree, moss it is just for aesthetic purposes.

Spaghnum on top of the pot gives a longer moist environment in the upper part of the substratem particularly after repotting, when the plant is sending out many new roots, it helps getting more and stronger surface roots.

Umfortunatrly, i find that birds drop by to collect the moss, and pull ath the young roots, making a mess of the substrate too..

ykbonsai wrote: i agree, moss it is just for aesthetic purposes.

Moss is certainly NOT just for decorative purposes.
Watch:
live.bonsaimirai.com/archive/video/spring-fundamentals
Lots of good information, moss is talked about in the first hour of the video.

Very interesting. I believe you can have the perks of the moss other ways without using moss though, and it will not make the watering a risky thing for a beginner, as the moss would do.
Thanks for the video, really a lot of good infos there.

Adding more to topic going on here.

@YkBonsai: Spagnum moss is not used for decorative purposes on bonsai at all or - the moss that is used for decorative purposes is not sphagnum moss.
Sphagnum moss is used for other purposes and can be beneficial.

crataegus.com/2012/07/05/the-moss-myth/

@Spacewood:
I am quite familiar with these videos. There were more than 250 videos. I've seen a lot of them. Not sure why, it make me cringe to see how this man treats his plants. The videos disappeared some time ago, but it seems the author had a backup and is placing them back. Unfortunately. Here's a topic I wrote about it long ago:

www.bonsaiempire.com/#18610

I cannot recommend watching this series. The method isn't easier than regular bonsai methods, the method probably is not at all suitable for your climate and the demonstrated results are pretty bad.

Unless of course when you think this is perfectly OK (go to 5:05)

LOL

This guy is not joking at all.

You know, I dont think I ever liked this guy works, just was interesting for me that trees can do in sphagnum and I thought this can be part of the discussion. This man really does bad things, thanks for showing this video to me.

Auk wrote: www.bonsaiempire.com/#18610

This takes me to Bonsai Empire website, seems invalid url.