Does it wear off when weather changes, and does it work on an ally and the user, or the entire party?
Flower Gift only works on Pokemon that are on the user's side of the field. It wears off when harsh sunlight goes away.
During harsh sunlight, Flower Gift increases the Attack and Special Defense stats of the Pokémon with this Ability and its allies by 1.5×.
Flower Gift (Bulbapedia)
Hope I helped!
