If you talk to the owner of the Pumpkin Landing Pub then he will assign you with some tasks to do. However, you cannot do all of these tasks at once so you will have to complete one task and come back later.
This guide will walk you through the tasks that the owner will need you to complete. Doing so will enable you to finish the Pumpkin Landing Sidequest
Pumpkin Landing Pumpkin Harvest Quest
The first thing you will need to do is to roll into the rafters to knock the piece of heart down to the floor. The owner of the bar will get angry at you and inquire on why you would do such a thing. Talk to him and he will begin to assign you tasks.
Pumpkin Landing Task 1
For the first task you will need to get yourself an empty bottle. If you do not have one yet you can follow our Skyward Sword Bottle Locations guide. The bar owner will fill your bottle with some Hot Pumpkin Soup for you to deliver to Knight Commander Eagus.
Commander Eagus can be located in the Sparring Hall on Skyloft so you will need to fly there.
If you can fly and deliver his soup in less than 5 minutes then the task will be completed by returning to the Lumpy Pumpkin.
Pumpkin Harvest Task 2
The owner of the Lumpy Pumpkin will have another task for you to complete after you finish the Earth Temple. So return to the bar and you will be able to go out back and meet Kina in the patch.
For this task you will have to carry a stack of pumpkins to their shed. This task can be quite challenging if you do not pay attention to what you are doing. The pumpkins will easily lose their balance so you will need to slowly walk until the pumpkins begin to sway. At this point stand still and gently tap the analog stick in the right direction to balance them. If you slowly move, stop, balance, and repeat you should be fine.
Lumpy Pumpkin Task 3
After you have moved the pumpkins to the shed you can go back and talk tyo the bar owner again. He will ask Link to comeback at night. So go ahead and sleep on the first floor bed and wait until night. One you have successfully stored the load in the shed, head back and talk with the sotre owner again. He will ask that you come back at night time, so sleep in the bed on the first floor until night.
Once you wake up, talk to the owner again and he will tell you to play your harp with his daughter. Once this begins you must simply play the harp to the rhythm to the bar’s customers. When the customers are not swaying their arms you can play however you like. If you successfully complete this then Link will get another heart piece.