A Compost Bin is an immovable container where weeds, crops, herbs, fruits and other Farming skill products are placed to make compost, supercompost, or rotten tomatoes. Compost Bins are located next to allotment/flower/herb patches:
- South of Falador (Explorer's ring 2-4)
- West of Port Phasmatys (Ectophial teleport)
- North of Ardougne (Ardougne cloak 2-4)
- North of Catherby (Camelot Teleport)
- South-east of Hosidius House (Xeric's talisman teleport or Tithe Farm Minigame teleport)
Players need 15 items to fill the Compost Bin, which they can then close to start the rotting process.
Players must use 15 supercompost-compatible items in the compost bin to make supercompost - even one incompatible item will make the whole contents into regular compost. This is the same when making rotten tomatoes. A message will pop up warning the player if they choose to impurify their compost bin.
To make ultracompost, a player must use 2 volcanic ash on a bucket of supercompost. Alternatively, 25 volcanic ashes can be used directly on a full compost bin containing supercompost in order to upgrade it to ultracompost.
Compost generally takes between 35-50 minutes to decompose inside the bin.
Players must use buckets to empty the compost bin.
Products of rotting
- Compost, made by rotting weeds and low level farming products.
- Supercompost, made by rotting high level farming products (see below) - pineapples are commonly used when making supercompost. Using a compost potion on a bin of regular compost will also turn it into supercompost.
- Rotten tomatoes, made by rotting 15 tomatoes.
- Ultracompost, made by using 25 volcanic ash on a bin of supercompost.
Suitable items for supercompost
Players may use an item on a farmer to check whether the item will make compost or super compost. The following items will always make supercompost.
- Pineapples (inexpensive and most common choice)
- Calquat fruit (a cheap supercompost-able item)
- Watermelons (grow on allotment and put directly in bin)
- Bittercap mushrooms (grow in mushroom patch west of Canifis)
- Tree roots (obtained when a tree is dug up from a tree patch)
- Coconut shells (use the empty coconut shell, otherwise useless and cannot be eaten)
- Papaya fruit
- Jangerberries (respawn on ogre island, west of Yanille)
- White berries (not recommended)
- Poison ivy berries (not recommended)
- Herbs excluding guam leaf, rogue's purse, snake weed, tarromin, marrentill, harralander, and ranarr weed.
- White tree fruit (after Garden of Tranquillity)