From Bulbapedia, the community-driven Pokémon encyclopedia.
The Pick a Peck of Colors Flower Shop (Japanese: フラワーショップいろとりどり Flower Shop Multicolor) is one of the chief landmarks of Floaroma Town. Notably, it is in this florist where the player can get his or her first berries, which are found planted outside and given out daily by a woman inside.
Another woman in the shop gives out the Sprayduck watering can (the equivalent of Hoenn's Wailmer Pail) to the player, allowing him or her to water berry plants, which makes them grow a greater amount of berries. The blonde woman behind the counter in the Flower Shop gives out accessories for Pokémon Super Contests in exchange for a certain amount of berries. A girl to the right randomly gives out one of the first ten berries.
A sign outside the shop reads:
Here are the accessories that can be obtained, and the amounts of Berries required to buy them.
In Diamond and Pearl