AusBonsai

Hi people.
I set a layer on this JBP in Nov (hoping to get a nice twin trunk out of it) but when I checked today the top layer of spag moss was very green... I opened it up to get a closer look and this is what I've got. The top and bottom of the layer section has swelled but no roots as yet. My question is where to now? Can I reset the layer? And what did I do wrong on the first one, if you can tell?

Any help would be great. Thanks

The tree has bridged the layer rather than put out new roots. You need to scrape back the new cambium and I would also increase the length of the layer. If I have trees that keep doing this I put 2 rings of fencing wire near each end to discourage bridging. I don't use bonsai wire as it breaks before it can be twisted tightly.

Thanks Tony
I thought it bridged but the swelling was what worried me. Haven't had a failure that swelled up so much... I guess I'll just extend the layer down and try again.
Thanks Grant

Looks like you did not scrape off the cambium properly after you took off the bark. the tree is still healthy so just try again in the same place but scrape the wood thoroughly. Swelling is just scar tissue covering up the wound. When roots come from the top of the cut (bottom of the new layer) the swelling helps to give more impressive nebari.