ground-layer

I started a ground layer on a BC a few weeks ago, and I see the callus forming nicely all around the trunk but no roots. The roots bellow are still growing vigorously, and so does the tree. Any advice?

Hey guys, I recently came across two articles, that, if I understand them correctly, state you can use ground-layering to remove grafts from 1. JWPs (https://www.evergreengardenworks.com/rootgraf.htm) and 2. Prunus mume (https://ibonsaiclub.forumotion.com/t8646-grafting-bonsai-prunus-mume)...