Auguste's sapling is given during the Enlightened Journey quest by Auguste to grow into a willow tree in order to obtain Willow branches to build the basket of the balloon for the Balloon transport system. The branches can also be cut off any existing willow tree in a farming patch or obtained by trading with other players. If the sapling is lost before it is planted, another can be purchased from Auguste for 30,000coins. However, as a willow seed costs 77 coins, this option is only reasonable for ironmen who are unwilling or unable to obtain a seed by other methods.
Auguste gives the player the sapling for free, only the first time. With it, he also gives the player a basket of apples, to pay a gardener to watch over it. Growing this sapling to a willow tree takes 4 hours. The sapling cannot be re-obtained after completing the quest, and cannot be stored in the seed vault.