My (limited) understanding is that this Thuja is quite easy to propagate
via cuttings. A quick google for "propagate thuja" (without quotes) turns
up quite a few articles -- one of these is
http://forums.gardenweb.com/forums/load/propa/msg09005225390.html
This variety is a hybrid and that means that every one that you see for
sale in a nursery has been hand propagated by someone and that makes me
believe that they really must be one of the easy varieties.
--
John McGaw
[Knoxville, TN, USA]
http://johnmcgaw.com