Like a Clockwork Time Bomb  

1. You must poison the Deathfist slosh barrels. To do this you must first harvest four Belchweeds. These can be found in front of the Deathfist Citadel.
2. After you have the Belchweeds you can poison the four barrels. They are located at:
• Derris - Tent near Deathfist Citadel ( 97, -36, -561 Copy )
• Drunder - Tent near Deathfist Citadel ( -65, -36, -739 Copy )
• Gorynn - Tent near Deathfist Citadel ( 93, -38, -832 Copy )
• Sullon - Tent southeast of the bridge ( -330, -28, -464 Copy )

The reward is a backpack, as well as opening up the Maintaining the Grassblade Flow quest.