The new green limbs or what is brown? The green pieces never root for me like this but, the brown older wood put out roots in just a few days. Green pieces I root in slightly damp dirt (also spritzed with water/little peroxide).
These are cuttings I took last fall but, never planted. They are still alive..WE never planted them and just left the bucket behind the storage building.
Also they seem to root near the surface...as what is below the roots has long rotted (standing on a rotted stilt). Originally I just a had a few inches of water in the bucket but, it rained into it after we left them outside.
I do this in the basement with just a florescent light. They have to be above freezing.