Well... then I feel a little mislead. This is what it says on the website:
"The Grove plays well with other 3D software, while integration with Blender adds the power
of a full 3D application. It allows you to import twigs from you favorite modeler – and export trees to
your favorite renderer. Blender is the ideal host for The Grove on Linux, Mac and Windows."
From this I thought I was able to create the trees in Blender and export it easily
- Terje