Long before there were refrigerators, people used a variety of techniques to preserve food. These include methods like pressure canning, curing, pickling, and dehydrating.
Vegetables can last for months when stored in a root cellar. Usually crops were put in the root cellar after the harvest so they could be eaten throughout the winter.
Root cellars are incredibly simple structures and fairly easy to make. Despite their simplicity, they are very effective at preserving foods without any power at all.
Not surprisingly, root vegetables do best in root cellars. Some of these include:
Beets
Parsnips
Carrots
Celeriac
Horseradish
Winter radishes
Salsify root