First of all, cool game. I played until I became a 'serious farmer'. Although that title is a bit confusing since my reputation was 'serious farmer', and yet I had not yet completed the checklist (which I did complete BTW. Kinda grindy).
I've also been looking at the development log, and the shop thing is certainly a great idea. Currently after the third upgrade, my money became virtual paperweights. Honestly even a shop that lets you buy criminally overpriced seeds would have been cool, just so I could easily decorate my island with cool trees, or experiment with what's the highest combo (I got Pink for best, but I really wanted to see what the two last ones were :( ).
Also, when I started getting 12 cards, I really started wishing that it were possible to automatically sort the cards based on their combo level. I generally like meta upgrades that give quality of life upgrades over percentage and addition type stuff, so a sorter or an auto combiner, stuff like that would be cool.
Also the explanation of the skills should be a bit better. Adjencency is a pretty vague concept in most people's brains. Is it 8 directions adjecency? 4? Does it cross rivers? Does it count trees on the opposite side as if it were a spherical island? Most annoying of all it seems the definition changes between the upgrades. For chaining together it seems that it is 4 directional, non-river crossing. However for variety, it is river crossing (still 4 directions tho). Now maybe it's for good reason. After all it is significantly easier to chain than get variety if they were both river-crossing. I'm sure I could invent up a few more ways why that could have reasonably been done. But the point is that it should be explained, because most people (including me) will just assume something and make stupid decisions until proven wrong. The recommend way is generally just to take a few pictures of your game, show what works and what doesn't, then shunt it into some little question mark button in a corner reserved for the curious.
Continuing on, let's speak of the difficulties I had realising the previous point. It took me quite a few tries to be able realise I could see the description of bloomed trees. I had tried a few times to see exactly what my chain bonus was, but couldn't see any description. About 20 minutes in, I accidently paused a little on the corner of a bloomed tree plot, and lo and behold, a description with the bonuses. This is... not great. The fact I need to focus on the *corner* of something generally indicates that the game is not very polished. Personally when I want to be able see different levels of info in one spot in a game, I generally like it when the scrollbar lets one change between levels of info. So, switching between no info shown, foreground tree info shown, and background tree info shown (Yeah the overlapping makes acquiring the info of some trees occasionally impossible. Not cool). This would work doubly well, since it gets kind of hard to see some plots when there are too many trees. So a scrollbar could be an easy way to switch between transparent mode, when all the trees have a significantly lowered opacity, and normal mode.
In the end, other than the final grind (Just filling the island entirely, then harvesting for 50k each time), twas an interesting time. Needs only some more time invested (I hear more of that is coming your way).