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Winter Composting

Composted organic material, or simply compost, is a vital component for keeping a garden vibrant and healthy. The organic matter provides key nutrients to the soil so plants and flowers will grow strong and robust during spring. These nutrients are what make your vegetables big and your flowers bright. Perhaps your garden had a productive summer thanks to your compost heap, but now, you want to keep your compost going as the days shorten and temperatures drop. If your winters are harsh, maintaining an active compost pile or bin can be challenging, but fortunately, there are a number of methods for composting during the cold winter months. Insulating your current compost, building a winter-ready compost container, or even indoor composting are options for the winter. With a little effort, you’ll be able to compost successfully all year long and have fresh, organic soil matter ready for your spring flowers and vegetables.

Composting Basics

Successful composting depends on the proper use of both green (nitrogen-providing) material and brown (carbon-providing) material. Green material is most of the leftovers from your kitchen. Brown material is typically leaves, and surrounding your compost heap with them will help insulate the heap as temperatures dip. Straw can be used as a substitute if your leaf stock is lean during the winter. Save up your green kitchen scraps and add them periodically, along with more brown material such as leaves or straw as necessary for a balanced heap. Be sure to turn the heap over to keep air circulating, even in the winter. But keep in mind that it’s not necessary to turn your compost as much during the winter as one would during the summer. As long as your center is well-insulated and does not freeze, the microbe activity should continue.

Prepare for the Cold

A gardener’s primary goal for their winter compost heap should be keeping the material warm, moist, and protected from the elements. This facilitates the growth and activity of bacteria, molds, fungi and microbes in your compost heap. Start with some green material from your kitchen in the center (food scraps), and surround it with insulating brown material, such as dead leaves, straw, or even newspaper. Continue to layer around the center, keeping in mind that it will need to remain warm, damp, and insulated even during the toughest freezes for your compost to stay active. Collect as much brown material as possible in the fall if your supplies will be scarce once the trees go dormant. Dead leaves are useful not only for providing carbon-rich brown material but for insulating your active compost. Store excess leaves in a separate pile and add more to the compost periodically as you turn your heap. It’s also best to start your winter compost heap in an empty bin; distribute any summer leftovers to your plants before you get started.

Winterize Existing Compost Heaps

The key to winterizing your existing compost heaps is insulating them from wind and moisture. If you are building a new compost heap, keep it out of direct exposure to the sun and rain. Any excess dead leaves will help insulate and warm the living matter in your compost heap as well as provide brown material. For larger compost piles, hay and hay bales are crucial: Not only will layering your compost with hay facilitate the composting process, but hay bales are excellent for shielding the core of your compost from its two biggest threats, moisture and wind. Sawdust is another ingredient that helps with moisture management due to its absorbency. Covering your compost during especially cold spells is highly recommended as well. Use a large tarp, piece of canvas, or burlap to further protect your heap.

Moisture Management in Your Compost

The challenge of maintaining proper moisture levels will vary depending on your location. If you reside in a dry climate, you may need to monitor your compost and add more green material to provide additional moisture, such as lettuce, tomatoes, or fruit peels. Water may even need to be added for gardeners in very arid climates. In wetter locations, covering your compost heap is essential not only for proper moisture management but also to keep wildlife from snacking on your kitchen scraps. If you find your compost is too damp, add more leaves, straw, sawdust, or shredded newspapers to absorb the excess moisture.

Compost tumblers or any waterproof container with a lid will work well to protect your compost from accumulating excess moisture from the elements. Failing that, a tarp or covering over your heap will suffice, as long as it is sealed on the sides. Too much moisture can slow the organic process in your heap, so be sure your compost has a healthy balance of brown material, as these leaves, straw, and hay will absorb excess water.

Indoor Composting and Vermicomposting

Many are hesitant to compost indoors because of the potential for odors, but when done correctly, indoor composting should be unnoticeable. Ideally, your compost container should go in the garage or in a dark pantry near the kitchen. You can start a small compost container in a 5-gallon bucket with a lid or use a round plastic garbage can with a lid. Make sure there is a proper balance of green and brown material in your indoor compost container and no excess moisture; too much moisture can inhibit the growth of your active compost and also cause odor-causing mildew. Balance between green and brown material in your indoor compost container is crucial for mitigating any odors. Add kitchen scraps to your compost bin regularly, following the same guidelines as you would for outdoor composting. If your indoor compost begins to accumulate too much moisture, add some shredded newspaper or cardboard.

Vermicomposting is indoor composting that uses worms to break down food scraps and compostable matter in a self-contained container. By using a specific type of worm, Eisenia fetida, known as the red wiggler, your kitchen scraps can be turned into organic soil matter. These worms can be found at any bait shop or farm supply store or even ordered online.

To start vermicomposting, use a rectangular plastic bin, about 10 to 14 gallons, with a lid. Run two perforated PVC pipes through the bottom of the bin lengthwise to allow adequate airflow, as oxygen is necessary for the worms to produce. Seal the ends of the PVC pipes. Fill the container about halfway with shredded newspaper or paper. Break up your food scraps into small, easily-digested pieces and start piling them in the corner, and let the worms get to work. Do not put anything containing meat, fat, oil, or grease in your vermicomposting container, as the worms cannot digest them. Be sure the bin stays between 55 and 77 degrees Fahrenheit and fairly humid. When spring comes, move your bin outdoors and the worms will continue their work. You can even add red wigglers directly to your soil for extra enrichment as you fill your garden for spring and summer.

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