How does the overgrowth system work? I have enough energy gathered but nothing happens when i click on the button
Things will only grow on your farm as long as overgrowth is active and it automatically gets refreshed as long as you have enough energy and if you do run out then the effect will automatically get reapplied the next morning after you've accumulated enough energy.
The "Bless my farm" Screen is only there so you can check how many turns are left on the effect and how much energy you have.