List the species you tried. Layering on the ground works if a branch is low enough. Just put a clump of dirt or rock on it to keep it in contact with the ground. Some species will not root and some species root easily. Ground layering you do not remove bark or cambium.I watch a lot of them. I tried the air layering method extensively in the last year or two. All the while, I am wondering how this is supposed to work when you are removing the cambium layer. Every one of the tree and shrub rootings failed.