Green Thumb Beginnings

Green Thumb Beginnings is a quest given to you by Dedue in Fire Emblem: Three Houses. This quest unlocks the Greenhouse feature during exploration.

Quest-Giver Dialogue
"There is a dish I would like to make, but I need more of a certain vegetable to do so. I was planning to grow it from seeds in the greenhouse, but if you'd like to help..."

Completion Dialogue
"You have my gratitude. The greenhouse is an invaluable resource. If we cultivate more plants, I'm sure we'll be able to cook a larger variety of meals."

Location
Given to you by Dedue outside the Officers Academy classrooms. He will give you Dedue's Seeds.

Rewards

 * Mixed Herb Seeds x5
 * Western Fódlan Seeds x5
 * Tomato x4
 * Renown 300 pts

Strategy
Dedue will give you Dedue's Seeds after you accept the quest. Go to the Greenhouse and speak to the Greenhouse Keeper to plant them. You may then cultivate them by "Infuse with magic", which is the only option available for Cultivate at this stage of the game.