This quest begins in Sanctum or Meridian.
In Silverwood or Freemarch, find six pumpkins. Then, find a Faerie Ring (mushroom icon on map) and click on the punch bowl to travel to The Realm of the Autumn Harvest. Now go to either of the two pumpkin patches in the zone and place the six pumpkins with the others you find there.
The reward is 25 Autumn Harvest Ambersaps.
While you're in this zone check out the event merchant and other daily quests!