EXPLOIT found (probably someone else found it before but Im gonna tell you anyway)
I dont know if this would go against the rules of this subreddit but I know that EA will send people to assasinate me. So you can unlock any plants that were behind a paywall or seedium with a simple sounding trick, it may be hard to set up. I dont know if it works in later versions but I made it work in a 2023 version.
All you do is create a custom level using ELM, and when it generates like the json code, you edit the code, there was like a reward line, and you change it to whatever plant you want to unlock(ofc you change it to its "software name" like red_stinger), and when you beat the level it just gives you that plant! I unlocked gold bloom for free!! Of course you also have to know how to add the custom levels to the game through file explorers and stuff its too long to explain if anyone really want to do that just look up tutorials on youtube.
I dont think this would work on the current version, as far as I know with ELM you can make custom levels to any version but I couldnt have the game open my levels.
I got reminded of this exploit when I was watching a challenge video about only using summoning plants where he went the effort and unlocked the seedium plants when he couldve just done this