Fungus on Japanese black pine

Hello bonsai lovers
I have a problem with my JBPs, I have 3 JBPs in bad conditions something like fungus in the soil:

Is it possible something like bad fungus? What can I do to treat it?
Please help.
Thank you

That could be a beneficial fungus. Has the tree been healthy?

Hello Jonas
Thank you for your quick response Jonas. The trees seemed good to me. I am going to upload some pictures. I really appreciated all the experiences and efforts that you were writing about bonsais![image|374x500](upload://cs

These are pictures from my little beginner bonsai garden. I really like and enjoy all your posts and bonsais
Again, thank you and accept my appreciation.
Kevin from Texas

1 Like

Looks similar to what happens when bits of Organic fertiliser remain wet and decompose on the surface! Have you been using organic cakes or pellets as fertiliser on the soil surface?

Hi Frank
Thank you for your response.
Yes, I fed them with organic pallets and it made the soil compact. What’s your suggestions? And what would I do to avoid this?

Simply make it your practise to change the soil surface as part of your fall maintenance routine. Scrape away the top 1/2 inch and replace with fresh soil. This is a good idea because it is usually the surface that compacts first. Then the free drainage remains and the necessity to repot is delayed.
If you do not like the appearance you can keep the cakes in tea bags, fertiliser cups, or place just below the soil level.


Your pines look great so I don’t see anything obvious to change. I like Frank’s advice about changing the surface soil - it can be a big help with colanders in particular.

Looks like beneficial fungus to me, Looks similar to whats in my JBP pots: