Possible fungi infection?

[Khaiba]

Hey guys,

I've recently noticed some white spots and other weird stuff on my trees and would like to ask you experts for advice

Any suggestions on how to treat this and where it might come from? Overwatering seemed unlikely to me, since the last few weeks had been so hot I actually felt like I underwatered.
It might have started with this juniper I got 2 months ago where the bottom part of the trunk was powdery white. As I had gotten it from a professional bonsai shop I didn't think it was anything harmful.

I unfortunately removed a lot of the white, yellowish parts before taking the pictures but it was similar to the ones above. Also, the outer layers of the trunk seem to coming apart and reveil yellowish fibers and very fine white, hairy fibers on the trunk underneath.

Any ideas and advice are appreciated!

 

[Anonymouse]

If I were you I would continue to watch it and if it gets any worse I would think about a fungicide. Hope it gets better!

 

[Shibui]

The white on the soil and roots is more likely to be mineral deposits. As the water evaporates any minerals in it stay behind and form this white crusty film. More common in hot weather when evaporation is higher than watering.
More watering can sometimes help reduce it but in areas with high mineral water this is inevitable. Does not usually hurt the trees.

Outer bark splitting is usually a result of the tree growing. Old bark splits and sometimes flakes away showing the new bark that has grown underneath.

I can't see any problem in either case.

 

[Leo in N E Illinois]

Ditto the above.

Rain, and or low dissolved solids water like RO or DI water will dissolve and wash away some of the salt build up. I don't see anything pathological.

All the trees you posted are potted too high in their pots. The roots should be buried. Especially trees in early development, the nebari should be kept buried. Keeping your bonsai "perched" on mounds of soil will result in "volcano shaped" tangled "claw foot" roots. Generally considered unattractive by traditional bonsai standards. You want spokes of a wheel arrangements of roots, which means the roots leave the trunk at a 90 degree angle, rather than the 60 degree or 45 degree angles that result from perching the tree on a mound of soil. Becomes quite difficult to correct once a tree becomes older.

Some do consider these "claw foot" root systems attractive. If that is the case, ignore my comments.