Level 40
Ferroseed evolves at level 45
Through leveling up; Ferroseed will evolve into Ferrothorn at level 40.
Ferroseed does evolve in Ferrothorn at level 40.
Ferroseed evolves into Ferrothorn at level 40.
Ferroseed evolves at level 40
Ferroseed evolves into Ferrothorn at Level 40 Ferrothorn
Level 40 ;-)
It evolves by leveling up. Ferroseed evolves into Ferrothorn at level 40.
Ferroseed will evolve into Ferrothorn.
Ferroseed begins to evolve at Lvl 40 so just train it up that level and it should evolve unless it's holding an Everstone.
You train it to level 40
Train it to level 40.