Thanks again guys,
Karl - I realize that I didn't post a response but your auto rust/cracking SBS was quite spectacular - quite inspirational and informative. Thanks.
Ok, the majority of the plant life is the dried moss that you use for floral arrangements. I got a bag of it at Michaels. It is basically a dried brownish color when it comes, but what I did was mix up some very diluted acrylic greens and yellow colors and soaked some batches, let dry and then pulled apart and glued in place. The only trick is to look for small branches that look like ferns and such.
The other (very limited) type of plants are the most excellent laser cut paper items from Kamizukuri: Here is one source---
http://www.tasca-modellismo.com/english/item4.html
I think that I got my batch from Hobby-link.
hope it helps.
Rick