Bag of Holding Dirt

This item can hold 64 cubic feet of various kinds of soil.
The bag auto-sorts various types of soils and separates them for retrieval.
Throwing a bag of dirt that is full causes the contents of the bag to violently explode outwards; dealing 2d4 +1 bludgeoning damage in a 15ft radius.
Bag must be fully refilled before this attack can be made again.