Old School RuneScape Wiki

Compost potions are made by mixing harralander and volcanic ash in a vial of water, giving 60 Herblore experience. Doing so requires level 21 Herblore.

A compost potion is one of the quest rewards after completing Garden of Tranquillity, and can be purchased with 5,000 reward points from participating in the Nightmare Zone minigame.

Players can use a dose of compost potion on a bucket of compost to make it into supercompost, or use a dose on a full compost bin to obtain 15 buckets of supercomposts instead. Players are advised to use these potions for their own compost bins instead of selling them away, as they will earn more by making buckets of supercompost. Note that the player cannot add a dose of compost potion to compost bins containing a combination of normal compost and supercompost vegetation (in any combination).


Compost potion (3)
Herblore icon.png Store value Alchemy value -
60 XP 36 54 -
Herblore.png Herblore level 21
Harralander potion (unf).png Harralander potion (unf) 1
Volcanic ash.png Volcanic ash 1


  • This potion is one of the few in the game that players cannot drink.
  • Prior to the release of the Nightmare Zone on 5 September 2013, compost potions were only obtainable as a one-time reward from completing the Garden of Tranquillity quest.
    • In addition, players could not make the potion via the Herblore skill; this was only made possible with the release of Fossil Island on 7 September 2017.