You could try AXYZ Design.
https://secure.axyz-design.com/
Here's a tutorial:
http://renderji.com/filter/tutorials/AX ... -tutorials
Plants
For trees and plants VizPark is good: http://www.vizpark.com/
We have bought their 3dsmax trees. With the 3dsmax trees you get MXS files. The MXS files can be used as MXS references in Rhino.
Here is an example where we use VizPark trees in one of our renderings. Around 10 000 trees.
Markus Wikar
Geometria Architecture Ltd
www.geometria.fi