This section is from the book "Save It For Winter.", by Frederick Fry Rockwell. Also available from Amazon: Save It For Winter; Modern Methods Of Canning, Dehydrating, Preserving And Storing Vegetables And Fruit For Winter Use, With Comments On The Best ... For Saving, And When And How To Grow Them.
Even if you have not raised enough of your own potatoes for winter use it will pay to buy them to store, as they are usually very much cheaper in September and October than later on. They keep best in a very cool, rather moist, cellar and must be protected carefully from light, as this not only endangers their keeping qualities but makes them less Valuable for food and inferior in quality, when it is necessary to keep potatoes where the air is very dry, instead of allowing free circulation of the air, it should be prevented as much as possible by placing the potatoes in large boxes (such as packing-cases obtained from a store). Line these first with several thicknesses of newspaper, and make a tight-fitting cover. Several days' supply should be taken out at each time, so that the box will be opened as infrequently as possible. Potatoes that are very early may be best kept for future use by being buried in the soil in boxes of convenient size. If put down eighteen inches or so below the surface in this way, they will keep in as good condition as the delicious "new potatoes" that are first ready to eat when the summer crop comes in. Potatoes are also one of the best Vegetables for keeping over in pits.
The sweet potato is entirely different in its requirements for winter storage from the white or Irish potato. It should be given a rather high temperature, fifty to sixty degrees if possible, and kept in a very dry place. The air should be permitted to circulate freely about the potatoes. Onion crates, such as already mentioned, may be used for storing sweet potatoes, and if placed near the chimney in the attic, will furnish about the right conditions.