Supercompost is a more potent version of compost and is used in conjunction with the Farming skill. Compost, super compost, and ultra compost reduce the chance of a player's crops becoming diseased whilst growing to rates of 1/4, 1/8, and 1/10 respectively, as well as increasing the minimum number of crops that will be received by the player upon harvest, even if those crops are protected.

There are two methods to make supercompost. The first method is to place 15 suitable organic items (see below) into any of the compost bins that are located next to the allotment patches found around RuneScape. Once the suitable items have been added, and the lid of the compost bin closed, the contents will begin to rot, taking approximately 90 minutes until completion. During this time, the player may not open the compost bin or add any more items. Once the super compost has finished rotting, the player may open the compost bin and extract all of the super compost by using a bucket on it. Each bucket of super compost collected by the player will grant that player 8.5 Farming experience. When used on a farming patch, each bucket will grant an additional 26 experience. The second method is to use a Compost Potion on regular compost. Besides, a player can also use a compost potion on a filled compost bin containing regular compost to turn it into supercompost.

As a rule of thumb, supercompost should only be used on farming patches that produce a valuable harvest (such as high-level herbs) and/or provide significant experience for each item harvested (such as watermelons). Supercompost cannot increase the yield of trees, fruit trees, or bush patches. Therefore, it is not recommended to treat those patches with supercompost if you plan to pay a gardener to watch over them, since there is no benefit other than the extra 26 experience granted.

If the player has finished the quest Garden of Tranquillity or have enough points in Nightmare Zone, they can use a dose of compost potion to turn regular compost to supercompost either on bucket (1) or compost bin (15).

Supercompost can also be purchased with reward points from the Tithe Farm minigame, costing 5 points per bucket.

Players can add two volcanic ashes to a bucket of supercompost to obtain ultracompost, or put 25 volcanic ash in a full compost bin that contains supercompost.

Suitable items

Item Cost to Fill
Pineapple Pineapple 1,725
Watermelon Watermelon 240
Coconut Coconut 20,895
Papaya fruit Papaya fruit 10,230
Mushroom Mushroom 5,460
Poison ivy berries Poison ivy berries 1,410
Jangerberries Jangerberries 4,335
White berries White berries 5,550
Toadflax Toadflax 20,085
Avantoe Avantoe 20,970
Kwuarm Kwuarm 16,800
Snapdragon Snapdragon 118,245
Cadantine Cadantine 19,695
Lantadyme Lantadyme 17,550
Dwarf weed Dwarf weed 7,410
Torstol Torstol 100,440
Oak roots Oak roots 480
Willow roots Willow roots 315
Maple roots Maple roots 420
Yew roots Yew roots 1,875
Magic roots Magic roots 19,980
Calquat fruit Calquat fruit 825
White tree fruit White tree fruit Not sold