In winter, the days get shorter, and the temperatures drop, but our kitchen waste stays the same and may even increase. As the weather gets worse, we find reasons to stay inside and cook more meals meaning more food scraps we need to dispose of.
If you have started composting and gotten used to quickly turning food scraps into rich organic material during the summer, you will need to adjust your techniques to keep your compost active through the winter months. It is possible to achieve year-round composting and to turn garden waste and green material into viable compost even during the cold months.
What Happens to Compost in the Winter?
As the temperatures drop and the sunlight gives off less energy, the composting process slows down and balancing temperature, moisture, and green and brown materials become much more difficult. In winter months, it may be difficult to access compost tumblers or digestors that are far from the back door. Food scraps and other food waste may attract hungry pests that have no other food options late in the year.
The colder months usually mean plants and yard waste will produce less material. Kitchen scraps will stay the same, but brown yard material would be limited to things like wood ash and pine needles. Both of these can further slow microbial activity and suspend the decomposition process. Adding brown material to larger compost piles or composting indoors can help produce soil during cold temperatures.
How to Keep Compost Active When It’s Cold?
Green kitchen scraps do not stop, and luckily we can make a rich soil amendment even in the coldest weather. In a cold climate, you will want to prepare your compost pile for the winter weather ahead of time. Taking a few proactive steps and strategically placing composting heaps can reward you with active compost even in the dead of winter.
Insulate
It is possible to build a compost heap or fill a tumbler with material that insulates the core compost. By keeping the very middle of the outdoor compost pile warm, a traditional compost pile can stay active through cold winters. The goal is to prevent the moisture in a compost pile from entering a deep freeze. Frozen compost will not break down and must be thawed before decomposition can continue.
Dry materials like dry leaves and straw bales can be made into a pile during winter. Bags of dead leaves and other fresh materials can be placed around or on top of a winter compost heap to keep it warm. These same materials can be used to line the outside of tumblers and digestors to insulate the decomposing materials in the middle. Insulation can keep a compost pile active all winter long.
Move Inside
The winter months are a perfect time to move a compost bin or tumble inside. Garages and porches can allow the compost to stay warmer than it would be out in the elements. Make sure animals don’t have access to the pile and lots of brown material is used to reduce excess moisture. The smell could attract pests into your home, so be careful.
Another benefit of moving a bin inside is that you will not need to go into the cold or wet like you would with a larger compost pile outdoors. Dumping things like coffee grounds and tea bags daily is easier if you don’t have to put on a snowsuit. Indoor composts are a good place to try worm composting to speed up decomposition even more.
Place Near Heated Structure
Building a winter heap near structures and heat sources is a good way to keep composts active in the cold. Placing compost bins close to exhaust fans from kitchens and dryers can increase the ambient temperature around your piles. Tumblers can be moved to where heat sources are or kept close to rooms that are always heated.
Be careful to make sure the compost piles don’t touch the side of the house or foundation, as it could lead to pest problems and water damage. Try to build the heat in a compost pile by having the correct ratio of dry and wet materials, as well as balancing carbon and nitrogen levels.
Protect From Elements
Straw bales and other temporary windbreaks can be placed by gardeners around compost piles in the winter. Building piles or placing bins where they receive full exposure to the southern sun can increase temperatures all winter long. Wind chill can reduce the bacteria population in compost piles drastically and stop the decomposition process.
When building a winter compost, make sure to block the sides and eliminate wind tunnels to keep the pile warmer. Place black materials like water jugs and plastic tarps under and adjacent to the piles to absorb more solar energy and hold the heat longer. Use bags of leaves and other brown material to convert compost faster.
Flip Often
Composting materials generate a ton of heat, and an active compost can keep itself hot enough to stay active if it is turned often. Every time a pile is flipped, oxygen reaches new areas of the pile, and microbes go to work eating the organic material. As the materials are broken down into nitrogen and carbon, heat is produced.
Some composts are easier to turn than others. Tumblers can be quickly flipped, making them ideal for wintertime work. Make sure the material inside the compost doesn’t freeze or turning; it might cause damage or injury. If the materials in a tumbler are frozen, make sure to let it thaw before trying to remove or turn the pile.
Best Winter Composting Methods
Composting in the winter is different than summer composting. With the exit of warm weather and high precipitation in milder climates, the techniques needed to make viable compost in the winter are important to learn. Organic compost is possible, as is a productive winter compost heap if the following methods are utilized.
| Method | Benefit | Issues |
| Indoor Composting | Active all winter | Limited capacity |
| Tumbler | Easy to flip and access in winter | Exposed to cold and excessive moisture |
| Compost Digestor | Low maintenance and good capacity | No way to flip or speed up compost production |
| Compost Pit | Inground compost stays warmer than pits exposed to wind and elements | Can freeze over, and is hard to keep moisture out |
| Worm Compost | Active all winter | Needs continuous food supply or worm population starts to decrease |
Indoor Composting
There are many indoor composters like Lumi and Bokashi that can steadily reduce your composting mass quickly and effectively. These systems can be used indoors year-round and are great for small apartments and homes that mainly deal with kitchen waste.
A countertop compost unit usually requires a tight-fitting lid and the right amount of C and N. moisture levels need to be just right, or your active compost could begin to stink and attract pests. These systems only work if you compost in layers alternating green food scraps and brown material packed tightly. The refuse of these systems can be used as compost tea.
Tumbler
Compost pile aeration is one of the best ways to keep an active compost going all winter. Outdoor compost heaps can be hard to flip in cold and wet winter conditions. Tumblers are an easier way to turn compost and only need to be kept from completely freezing to work all winter long.
Tumblers can be packed with materials, and when fully rotated daily, keep the pile active. It is the easiest way to turn a compost pile during winter and can be placed near your back door. Keeping tumblers close to a heat source can keep them from freezing and speed up compost production.
Compost Digestor
Compost digestors have a range of benefits that make them good for winter use. They seal well and can easily be insulated, keeping bacteria happy and active. It is easy to keep pests out of these composters, and they are positioned directly on the soil to promote soil microbe interactions.
Most compost digesters have two compartments allowing you to fill one while keeping the other compost pile active. Outdoor compost keepers are hard to mix as pitchforks can’t reach the pile effectively. These winter compost heaps will be ready in the spring but cannot be rushed or moved easily.
Compost Pit
Organic compost can most easily be made in a pit in your backyard. A compost pit is naturally protected from wind and will stay warmer than above-ground composting piles. Active compost piles should be covered with tarps or other waterproof materials to keep the rain and moisture out.
Outdoor compost heaps can be exposed to critters and need to be covered or fenced off. Finished compost can be collected from the bottoms of these piles in the spring, and their top material is flipped to take advantage of the warming conditions. Make sure to harvest compost from these pits in the fall so there is enough room for new material all winter.
Worm Compost
Taking advantage of the speed by which worms create vermicast can help you manage kitchen waste during the cool winter months. When outdoor composting is ineffective, you can keep a warm bin in the garage or porch and break down all your food waste.
During the summer, when you have yard waste again, you can switch back to larger compost heaps and add the worm material to kick-start the pile. Make sure to keep a steady supply of food for your worms once you begin feeding them so they can maintain their population.
Winter Composting Issues
During the winter, there can be a lot of issues that make composting a challenge. If you don’t plan ahead, you might not have rich compost for your spring gardens. Worse yet, you may need to start throwing your biodegradable into the trash and not the compost leading to landfill waste. Expect these common problems during winter compositing operations.
Slowed Microbial Activity
As the temperatures drop, microbes slow down and stop reproducing. If the temperature falls low enough, then you will have inactive compost as the bacteria and critters go dormant. When the temperatures rise in the spring, the microbes will wake back up and continue the process. Keeping the temperatures high will keep your compost bacteria happy.
Lack of Brown Material
It can be hard to get brown material for the compost in the winter. Once the trees have dropped their leaves, you will need to be creative to balance your kitchen scraps. Collecting lots of carbon-rich waste in the fall and saving it to add slowly through the winter can help you keep your pile active.
Poor Access to Compost
Walking through the yard in the snow to throw some vegetable peels into the compost is not fun. Ice, puddles, and bone-chilling gusts can make a simple trip to the compost a nightmare. Bundling up can help, but to really avoid this crisis, it helps to have a compost you can move. Keeping your compost close to your backdoor or, better yet, in your garage can help you avoid compost frostbite.
Excessive Moisture
Snow, rain, sleet, and everything in between will try to find its way into your pile. With the reduction of brown materials and lower evaporation rates, wetness can build up very quickly. An overly wet compost will breed fungus, have foul odors, and attract pests. Covering composts completely and utilizing drain and water reduction components of many composting systems can help keep your pile dry.
Hungry Scavengers
As things die and food sources disappear, pests and scavengers will get hungry. The wet and hard ground makes burying food waste deeply difficult, so these factors may lead to an increase in scavengers. Pests in your compost pile can make messes and spread diseases. Make sure food scraps are buried deeply and your compost pile is fenced in or protected from wild animals.