Composting in winter typically involves keeping your compost pile insulated. But the challenges associated with keeping a pile warm enough in winter mean that compost piles often go dormant during this season. A composting technique with plastic bags is a simple way to keep composting all year long--by bringing the compost indoors. This method requires little to no attention in any season. The limited oxygen in the sealed bags, however, slows the composting process. Still, the convenience of this method for year-around composting makes it a viable option.
Layer wet (food scraps, green plant trimmings, etc.) and dry (leaves, straw, etc.) materials in a garbage bag until it is about a third full. Thin, even layers work well. Sprinkle one teaspoon fertilizer and 1/3 cup lime on top.
Layer more material as before until the bag is about two-thirds full. Add another teaspoon of fertilizer and 1/3 cup lime sprinkled over this. Repeat with the final third of the material and top with one more teaspoon of fertilizer and 1/3 cup lime.
Pour in about one quart of water and close the bag securely. Place it in a heated garage or basement and leave it undisturbed throughout the winter.
Check your compost about one year after placing it in the bag. If the contents have been reduced to about half their original amount and have a rich earthy smell, the compost is ready for use. If materials are not completely composted, shake the bag, tie it up again and give it a few more months.