Separate cellars are occasionally used for storing fruits, such as apples. Apples are one of the crops that give off enough ethylene gas to hasten the overripening or spoilage of other crops stored nearby, although this effect is variable and many farms successfully store vegetables without segregating their apples. Water, bread, butter, milk, and cream are sometimes stored in the root cellar. Items such as salad greens, fresh meat, and jam pies are kept in the root cellar early in the day to keep cool until they are needed for supper.