Thanks for playing, I really appreciate it and it was nice to see that you liked it! By the way, an uproot/removal feature as well as a grid tracker are both going to be added in the next update (I'll update after the jam ends).
The problem with the parasite plants is that they inhibit growth for each other as well, so if you put two of them next to each other they both get stuck (only realised this after the jam deadline), which is what you've experienced. This is also why I'm adding the uproot/removal feature with the next update!