Btw, you can also cover lower branches of a plant to do layering. It will throw roots if part of a branch is placed in a dark and humid place (soil).
I don't kno whats easier to root rosemary or the potato in our 7th grade sci class project.
as said above air layering is easy easy.
I had a rosemary plant that was rather unruly, so 1 of the branches
laid over, and over and OVER until the lambs ear in the pot next to rosemary caught it,
the branch landed on top of the soil in the L-ear pot and when to sweep up the rosemary had rooted in the lambs ear....
so! the moral of the story is........
keep an Eye on the lambs Ear
or it may end up having Rosemary's Baby
.
.