HelpfulGardener.com

Hi there,

I have a small ficus, which I have had for just over a year now. It seems happy but recently I have noticed what appears to be a layer of green moss or mold growing on the soil. The soil is 100% akadama and I am not sure what the cause of this growth is. Below are a few images of the bonsai and a couple of close ups of the soil where you can see the green:

https://dl.dropboxusercontent.com/u/101 ... 201338.jpg

https://dl.dropboxusercontent.com/u/101 ... 201345.jpg

https://dl.dropboxusercontent.com/u/101 ... 201353.jpg

If I take one of the akadama pellets and break it in half I can see that the green growth is only on the outside of the pellets:

https://dl.dropboxusercontent.com/u/101 ... 201645.jpg

I would really appreciate any thoughts on whether this green stuff is moss and whether I need to be taking any steps to ensure the health of my tree.

Many thanks!

Green stuff is not moss, it is algae.

You have had the tree for a year. Have you repotted it in that time?

Here's a really nice article about repotting bonsais:

https://www.kaizenbonsai.com/shop/repotting_guide.php

You will note that one of the signs it is time to repot is algae growing on the surface of the soil.

It may be that you are keeping the soil too wet, too much of the time, but it may just be time to repot.


FOR THE BONSAI EXPERTS: This tree has a very obvious trunk chop. Since trunk chop is a common procedure in bonsai production, what do people do to disguise that, make it look more like a miniature tree and less like a big tree that was chopped off?

Hi rainbowgardener,

Thanks for your reply. I repotted the tree around April 2013, not long after getting it. I guess I will have to repot it soon.

Thinking about it, it is possible that the soil has stayed too damp. Over the winter the location I have it in, means that it receives limited sunlight, so perhaps I have watered too often. I take it that damp encourages algae to grow?

Thanks

" I take it that damp encourages algae to grow?"

Yes, if it dries out completely the algae dies. You may need to leave more time between waterings. Be sure you water thoroughly when you do, then wait until the top inch or so of soil is dry before watering again.

But yes after a year, it is time to repot again. Repotting should be done in the spring, when the tree is just starting to grow again:

https://www.bonsai4me.com/Basics/BasicsW ... Bonsai.htm