After you defeat gym leader Viola in Santalune City, you can go north through Parterre Way, which leads to Lumiose City.
Battle and Catch
In the flowers, you can find Ledyba, Ralts, Skitty, Budew, Combee, and Flabébé. Walk in the red flowers to find red-flower Flabébé. Walk in the yellow flowers to find yellow-flower Flabébé. You can find orange-flower Flabébé and white-flower Flabébé when walking in any flower colors in this route, but they are very rare.
In the southeast side of the maze, you find a Super Potion. In the northwest part of the maze, you can find an Antidote. In the northeast part, there is a Great Ball.
In the northwest part of the maze, Gardener Wheaton challenges you. He has a level 10 Corphish.
Skating around the fountain are some pokémon trainers. Roller Skater Calida has a level 10 Torchic.
Another trainer skating around the fountain is Roller Skater Roland. He has a level 10 Pidgey.
North of the fountain, on the right, Poké Fan Agnes challenges you. She has three level 7 Burmy, each of a different form.
In the area north of Agnes, in the middle, there is a Poison Barb.
To the left of that area, there is Preschooler Mia. She has a level 9 Budew. You receive 144 Pokédollars for winning. To the right of the middle area, there is Preschooler Adrian. He has a level 9 Magikarp.
Northeast from there, you find Gardener Fabian. He has a level 10 Corphish.
In the northeast corner of the maze, there is an Ether. In the middle, at the top of the flower path, is Poké Fan Gabe. He has a level 7 Pichu and a level 9 Pikachu.
In the northwest corner, there is Gardener Grover. He has a level 10 Corphish.
West of Gardener Grover, there is a Net Ball.
At the north end of Parterre Way, in the middle, you meet Sina and Dexio, who tell you about the new Fairy type. When you're ready, go north. Keep going north and Dexio will give you TM27 Return.
When you're ready, go north to Lumiose City.