The red ones on the left are apples from some cheap modeltree. The middle three are just small pieces of foam. The stuff on the right are very tiny strips of wood from a plant out the garden. I can't remember wich species it was, too long ago.
I think you can also use seeds from flowers or weeds. Maybe you have to paint those however.
Long time ago I posted something here. Still not much done on the layout but I have build some freightcars. The unpainted flatcar is a Tichy kit wich I build a year ago. The one to the front is build from wood and some leftovers.
I forgot the coupler pockets but I can fix that. The trucks are uninstalled and needs some paint first. Also a break wheel has to be added.