xearth in KDE root window?

[Fritz]

Maybe someone knows the answer to this question:
How can I run xearth in the root window (i.e. as the "background")
in KDE?  (xearth runs fine under Gnome and in "bare X".)

Apparently KDE has commandeered the root window
by covering it with a frameless, borderless window of its
own.  Is there any way to get around this?

I know that xearth can be run with the "-noroot" option
so it runs in an ordinary window, but I want to run it
as my "background" in KDE.

TIA.

Fritz