AusBonsai

Hi this topic may have been done before but my Chinese elm has green mould on the trunk and branches Could someone please tell me what is best to remove it. Thanks in advance.

Green Mould Maybe a picture would help work out what it really is. Could be a number of things - moss, algae or lichen immediately come to mind, all of which should be killed by iron sulphate, vinegar or several other moss treatments you can get at a nursery. Scrubbing with a toothbrush sometimes removes moss but is really difficult on rough barked trees.

shibui wrote:Green Mould Maybe a picture would help work out what it really is. Could be a number of things - moss, algae or lichen immediately come to mind, all of which should be killed.

Can this be a desirable characteristic on sum trees? Or like you have said must be killed?

When i was in Japan I did see an elm that had moss all over the trunk and I did ask about needing to remove it and they replied no we are not removing it we put it there.

There was also a small fat elm with moss all over the trunk but when i asked about that one they told me it was a fat rock with the elm on it.

You could not tell it was a rock so yes it can be a desirable characteristic on sum trees.

Thanks for answering. Will post a pic asap. It is not bad but has a little on the branches.

Can this be a desirable characteristic on sum trees? Or like you have said must be killed?

Depends on how you see it and who you listen to.
Hiro made several comments about moss on the nebari, trunks, and branches. He said at one stage it reminded him of a person who has not had a shower so clearly, to him it is very undesirable.

There is some thought that moss growing on the bark of a tree can keep it too damp and encourage the bark to rot. I was also told that moss on the branches will prevent new buds from growing there (shaded by the moss)
I believe that lichen does little harm to the bark. It actually indicates excellent air quality and conditions.

I think if I had an old swamp cypress or other swamp tree I would love to see some moss, etc growing in the branches because that's what happens in their habitat but one of the visiting experts was critical of too much non bonsai stuff - moss, stones, etc because it takes your eye away from the bonsai. As usual, everyone has their own opinion and maybe everyone can be right at the same time?

Mount Nasura wrote:

Can this be a desirable characteristic on sum trees?

NO! Moss releases acidic compounds which break down whatever they are growing on and most importantly in promotes decomposition of the bark by retaining moisture. You can grow a couple of ''mossy'' trees for the fun of it but remove it from good trees! Especially corky elms which have very soft bark.

I don't mean too be high-jacking this post, and this is clearly not an elm, however similar situation here is the moss I was enjoying on my mel, so it should go asap?! It appeared naturally and I thought it added an element of age, or like it was a swamp mel or near running water, sort of realistic?…however health takes precedents so just say the word and its gone!