I love the idea! And I think it could maybe be extended into the museum too?
The idea would be that some sort of "famous eccentric artist" becomes a fan of your town?s museum after you have donated a certain ammount of pieces of art, and the character asks if they can open a display in your museum where he will make "art based on the local flowers" and make really cool flower arangements in beautiful vases?
You would be asked for specific bunches of flowers, from simple easy stuff like "3 red tulips, 2 white tulips, 4 red roses" to like high level "6 purple pansies, 4 pink cosmos, 1 jacobs ladder" (This would be the one kind of donation that only appears in your museum until the next day, so the "artist has time to work his magic".
Once youve donated them all, the artist would be so happy with "Your Town?s villager?s dedication to gardening and art" that they would "Make arrangements" so special fertilizer is stocked at Leif?s shop that always ensures 2 flowers will grow (considering there is space, high chances of rare colors) in adition to the normal flowers that would pop from breeding each day.
I might be getting a bit off topic but I think its a nice idea!