Moin, I played the Game and it is fun. I also have some ideas.
Why don't make plants, that have unique traits. Like: If this plant is harvested give a 1,1 multiplier for the rest of the round. Also a combo-system, when you harvest plants of the same. Like 1,1 multi.
I also think of a trait that gives the field you harvest the plant a permanent booster, like 1,05 multiplier or so.
LG friend from Germany