By placing either Hoardapult (R1) or Loot Hoard (Trait) on a spawned seed on Garden of Terror, the seed will move (in any direction) instead of being unaffected by one of the two abilites.
I discovered this in quick match when an enemy Hogger player did this with Hoardapult.
Edit: I have sent an email to HeroesBugAttachments@blizzard.com with the replay as well as additional info