Mint plants are unlock by account or by player

Hi,

I'd like to know if the mint plants are unlocked by account or by player, I mean, in my account there are 4 players but only like with 2 are getting close to the 100 mints to unlock the plant and taking into account the time left, it seems unlikely that the other two players will get 100 mints. So, if in a player the mint is unlock, it will be available only for that player? If that so, you should leave the batlle arena separate for each player so all have the same chance to unlock the plants. Thanks!