In battle, Fink Flowers can attack physically by whipping their wines at one of Mario's party. They can also use moves such as Pollen Nap and S'crow Dust which can put someone to sleep or turn them into a scarecrow. They also then to heal themselves whenever their HP gets low. Fink Flowers are also known for their high HP.
Fink Flowers, being plants, are weak to Fire moves so Mario should use his Super Flame on them. Having someone wear a Trueform Pin and another wearing a Wake Up Pin.