Change mesh/object of emitted particles

Hi.

I want to do a simple animation with only a few frames: A field of growing plants.

I created 6 objects (3 sets of different growth statuses with each 2 variations) and use them in a particle system.
How do I manage to use one set of objects/meshes for the first frames

  • switch them to another set of objects/meshes a set frames later
  • and keep the location of these particles?

Found a nice solution on StackExchange.

If you have more “groups” you can combine multiple Mask Modifiers then.
I attach a demo file: switch.blend (694 KB)