White tree fruits can be picked from the last remaining white tree at the Varrock Palace garden, after completing Garden of Tranquillity. This is the only method available to obtain a white tree fruit.
They heal 200 life points each and restore 16 run energy when eaten. They spawn at the rate of 1 every five minutes, up to the maximum of four at a time. They grant 12 Farming experience when harvested. Because they are free, these can serve as a substitute for energy potions. However, this is not recommended, due to the fact that they restore a lower total amount of run energy and take far longer to obtain. In addition, the fruits can be used to make supercompost.
Ube, who attends the beacon north of Varrock, will ask you for this fruit, in exchange for tending the beacon for you while lighting it, as part of the All Fired Up minigame.