Instructions
Travel to Goldenrod City and defeat the gym leader there to receive the "Plain Badge."
Visit the flower shop in the same town to receive a new item, the squirt bottle.
Travel up Route 35 until you reach a small tree barring your way. Use the "Cut" technique to remove the tree, then continue north up Route 36. Travel up the road to reach Route 37.
Speak to the person standing next to the plant that is obstructing your entry to Route 37. You discover that the plant is actually a Pokemon, and you have to defeat it in battle to proceed.
Use the squirt bottle on the strange plant to begin the fight. Defeat the Pokemon or capture it to win the battle. You will receive four berry pots from the person who witnessed the battle.
Open your character backpack to equip and activate the berry pots. The pots are in the "Key Items" pocket of the backpack.
Select a berry from your backpack then "Plant" it in one of the berry pots. The berries will grow and net you more berries. Berries take different times to grow depending on the type of berry. Water the berries by using the squirt bottle at least once every six to eight hours to get a bigger harvest.