As you enter this route, the path splits into two. One path goes northwest while the other just goes directly west. Go to the left as Shauna will prevent you from taking the upper path.
Before heading to your destination, keep an eye out for an opening to the south. Enter it and you will be greeted by a child and her grandfather. They will ask you to take care of their Berry field.
They will give you instructions on how to plant berries. The grandfather will then give you Oran Berries(x5) and Pecha Berries(x5) to start off. He will then tell you that berries need watering. You will receive a Sprinklodat to water the plants.
In the northwest and southeast corner of the field ar Composters. You can use the composters to make 3 berries into mulch.
To know more about berries and mulch, head to the house on the northeast part of the field. The child will tell you about mulch while her grandfather will tell you about berries
If you want to plant a berry with mulch, use the mulch on the soil then place the berry. After planting the berry, water it. You can check back on the berry field occasionally to see if the berry needs watering.
Before leaving the field, head to the southwest corner of the field to find a Miracle Seed. Exit the field and then head left.
Keep on heading left until you reach a bridge that is blocked by a Snorlax. Apparently they cannot wake it up as they do not have the Poké Flute anymore.
They will tell you that the Poké Flute is at the Parfum Palace, which is just past Route 6. Head back to the fork in near town and go north to Route 6.