I have a Warszewiczia coccinea that has grown to about 6 feet in height in a large pot over the last 3 years. I have taken multiple cuttings from it but so far I have been completely unsuccessful in propagating it. I have had some of the cuttings remain green for several weeks but there has been no sign of any root formation whatsoever and the cuttings eventually go brown and dry. I have tried new wood, old wood, tip cuttings etc. to no avail and although it flowers profusely it never has seeds that I can identify. Can anyone give suggestions for successful propagation?