I think the game has a lot of potential, but I have a few comments to add (please note these are opinions of 1 very insignificant person - me :D  ):

1) I think it would help significantly if there was a better understanding of how to have the plants grow and propagate (unless i missed this... if i did, oops), as well as what the main goal really is (spread greenery, but how much exactly? or how many items are available to drop?). It would help a lot for planning ahead.

2) I think it's counterintuitive to have a "campaign" as well as a creative mode, but I can understand where that thought comes from. Minecraft is an example of what I think would work out well, where both aspects are combined into one. I'm not too sure how else to go about it either, sorry that I cant help here

3) Tying to point 1), I think each species has it's own pro's and cons, and I really think you should highlight/mention them (at least slightly via card details, or text?), similar to how you showed what planters are and everything. Using a stage to explain the use cases between the plants work, but the nuances get lost imo.

Overall, I really do enjoy the game, and its heuristic approach,  but I feel like there are just some things that need to be explained.