GroIMP can be started without its graphical interface, in headless.

You can find an example here.

Download the example project and run in with java -Xverify:none -jar core.jar –headless PATH/TO/THE/MODEL.gsz. The model will run in background, grow few steps of the plant model, and export several views for each step.

You can have a look at this tutorial for more information. Further a tutorial for using command line parameters in the model can be found here