The door in front of the previous moon will open up, revealing another checkpoint flag and a hole that will lead to the secret flower field. Drop down the hole to find some kind of UFO-like machine taking all of the flowers. Capture the nearby Uproot, then stand underneath the machine and stretch your legs, holding it in place to deal damage to the thing. This will trigger the beginning of a boss fight.
BOSS - Torkdrift
As with the majority of the bosses, this one will also go through three phrases, with minor differences between the three of them. All of the phases will begin with Torkdrift spawning three sets of blocks, which you will need to destroy by stretching your legs with the Uproot underneath them. Make sure you hit the blue thing in the center and while doing this, the boss will attack by shooting lasers at you, although you will see a target beforehand.
Destroy all three bricks and Torkdrift will flip over, which is your chance to do the same thing as in the very beginning. After taking damage, Torkdrift will begin firing lasers at the ground, causing shockwaves. Remember that the Uproot does a little hop after releasing the button when stretching, so use that to avoid damage. The shockwaves are simple at first, but will get higher as the fight goes on. Repeat this two more times to finish the fight and secure another Multi Moon (Defend the Secret Flower Field!) .