If you live in a cold climate where the temperatures stay below freezing for 
most of the winter, you can store you garden produce outdoors.  The vegetables
can be kept in shallow pits, in small barrels, nail kegs or in unused cold 
frames.  

Outdoor storage is not suitable in climates where winter temperatures
stay above freezing for several days at a time or where winter rains are 
frequent.  If using kegs or barrels, line them with clean straw,
then add the vegetables.  Cover the vegetables with more straw or dried leaves.  
Pile on enough soil to prevent freezing.

If you dig storage pits, locate them in an area with well draining soil.  Dig 
the pit no more than 1 foot deep and line with straw.  Place the vegetables in
a conical mound and cover them with 6" of straw.  Then add 3" of soil.  Allow a 
bit of the straw to poke through the soil for good ventilation.  As the
cold weather becomes more severe, add 5-6" more of soil.  When the surface 
freezes, 6-8" of manure will help to generate heat.

Once you open the pit or barrel, all the vegetables must be used, so it's a good 
idea to make plenty of small storage areas or containers instead of only a few 
large ones.
Source: USDA
