There are five beanstalks in Minish Cap. Below is a list of where they are and how to make them grow, and what is on the clouds that they lead to. They are listed in order of how soon you can get them.
Beanstalk Locations and Fusions to Unlock
Beanstalk 1
Where the beanstalk is: The peak of Mt. Crenel
Who to fuse kinstones with: Melari
What type of kinstone is needed: Red triangle wedge
What is on the cloud: A piece of heart
Beanstalk 2
Where the beanstalk is: Eastern Hills
Who to fuse kinstones with: The forest Minish who lives in a house
in the southwest corner of Eastern Hills
What type of kinstone is needed: Blue S-curve
What is on the cloud: 200 rupees and 200 mysterious shells
Beanstalk 3
Where the beanstalk is: Western Wood
Who to fuse kinstones with: The forest Minish who lives in a house
in the southwest corner of Western Wood
What type of kinstone is needed: Blue squarish
What is on the cloud: Some rupees and a red kinstone piece
Beanstalk 4
Where the beanstalk is: Wind ruins
Who to fuse kinstones with: The forest Minish who lives in a crack in the ground
What type of kinstone is needed: Red long teeth
What is on the cloud: Large quiver
Beanstalk 5
Where the beanstalk is: Lake Hylia
Who to fuse kinstones with: The forest Minish who lives in a crack on a ledge that you can reach by swimming to a vine
What type of kinstone is needed: Blue squarish
What is on the cloud: 200 rupees, 200 mysterious shells, and a piece of heart