Definition:
Winter sowing is a method of starting seeds outdoors in winter. This is generally done with seeds that require a period of cold stratification. The method takes advantage of natural temperatures, rather than artificially refrigerating seeds.
The Method (taken from suite101.com as it is closely matched what I did):
Winter Sowing is almost as much a philosophy as it is a method. It's not about going to the garden center and plunking down your hard-earned cash for a bunch of supplies that cost more than the seeds you are trying to grow. In Winter Sowing, the containers you use are recycled from things you've already purchased. Milk jugs, two-liter soda bottles, salad take-out containers, and big plastic jars (the kind pretzels come in at warehouse clubs) are all popular winter sowing containers. The only requirements are that it must be able to hold at least three inches of soil and it must have head room for the growing plants. Drainage holes should be cut into the bottom, and air transpiration holes or slits should be cut into the top of the container. Fill the bottom of the container with at least three inches of whatever soil you like best, and moisten it well. The water should drain through the holes you've made in the bottom. Once your soil is wet, sow your seeds according to the package directions. Cover your container, and set it in a spot outdoors. The only place containers shouldn't be placed is under awnings or overhangs, since the seeds will be watered in large part by melting snow, and then spring rains, and you want to make sure they get enough water. Keep your eye on your containers. Condensation is a good thing. If there is no condensation, it either means that you have too many transpiration holes (tape over some of them if this is the case) or your soil is drying out. As spring arrives, and the air warms up, your transpiration holes should be made bigger and bigger, until you remove the top of your container entirely. This is the winter sowing way to “harden off” your plants. After they are hardened off, simply plant your transplants out in the garden.
( Pictures )