mangrove roots style blocks attached to bottom of custom tree

I have made custom blocks similar to mangrove roots for my custom tree, this includes a muddy variant. However, I do no like the default mangrove design for my modded tree. I was wondering if there was a way or some sort of workaround that allows me to attach a mangrove root style system (with my custom roots) to my tree without using mangrove tree and instead my own.