In message , Douglas
writes

Will someone with the knowledge please discuss the situation where one sets
the cutting aside for a while to allow the cut-wound at the bottom of the
cutting (just under the node) to form a dry callus.
I have the feeling that a "woody type!" cutting would be appropriate but a
soft pappy cutting would be a non-starter, - not able to form a callus..

It is more to do with the tendency of the target to rot if its newly
damaged cells are placed in contact with soil or water. A lot of the
plants from more arid areas will stand a much higher chance of rooting
rather than rotting if you allow them to form a callous before putting
them in soil. Geraniums and pelargoniums for instance benefit enormously
from this.

Equally plants from water margins tend to expire very quickly if they
become dry for any extended period of time. In between you have to
experiment. I am inclined to try most woody cuttings direct into soil
some with and some without rooting powder. Unless I know that they rot
easily.

Regards,
--
Martin Brown