Level 23
You have four branches to heal, and six turns. This means NO branch can take more than 3 turns to heal.
If you do not start with the top right branch, it will take three turns to heal it.
If you start with the top right branch, both the branch left of it, and the branch below it will take a minimum of three turns each to heal.
The level is impossible. It was actually not bad until hitting this brick wall.