Hi there! I have a question. I am new to the bonsai art for about 2 years.
I live in a flat and my bonsai trees pretty are much doing very well during spring, summer and fall. The problem I have is that I can't get Deciduous bonsai's to live during the winter. Some of them I know I watered too much, took out a chinese elm out of the pot in spring and saw that it was root rotted. (maybe it's a usual error for the beginners to water too much when the plant looks dry).
I must tell you that I live in Romania and here, the real bonsai soil (like akadama) is pretty damn hard to get. Just one online sells it and it pretty expensive.
The trees sit on a window enclosed terrace that never drops below 12-13 C* during the winter.
OK. so to summarize it, I think the question is how do I know how much to water deciduous during winter (because I think that is the cause that is killing them.

Thank you very much and I hope you much more experinced people can help me with some advices.

I would venture to say you are keeping them on the warm side. Besides that, if a plant does not have leaves, it uses very little water: The pot can be very dry.

Try alternative materials. Go to a hardware store and see whether they have clay-based fillers for in houded/floors. Look for baked kitten litter products, look for lava. Akadama is certainly not the only thing you can use.

This should be useful.
It tells you about the different sources of a baked clay product called ''Moler clay''

www.bonsai4me.com/Basics/Basicscatlitter.htm

Ed

There is no such thing here. I have a cat and here you can find only silicone and plain sand for cats.
I found this thought www.dedeman.ro/ro/gradina/gratare/acceso...a-vulcanica-3kg.html
volcanic rock.
Maby I can crush it.

Maybe this is a good place to ask about what's available in Romania:

ro-bonsai.ro/forum/index.php

Ok sorry we took the topic into materials. That was not the issue.
So basically the I understand that the idea is that I can keep them pretty dry during the winter.
Or I can use spraying because the air can get pretty dry in the cold season. In latest years we got very little snow, just plain dry cold.
I have a hygrometer on my terrace and in wintertime I saw that the humidity can drop to 30 %.

we just keep them outside in the freezing cold, insulate the roots though.

Claudiu wrote: Or I can use spraying because the air can get pretty dry in the cold season.

When it's cold, there won't be much evaporation. I never spray in winter. In our dutch climate, I hardly even water them in winter.