Can You Compost Outside In Winter?

Technically Yes. You can compost outside in winter, but it will take longer than in summer. The reason is simple; the decomposition rate depends on temperature, which drops once it drops.

Decomposition, the core of the composting process, is rapid between 90° and 140°F (32 – 60°C). The decomposition rate decreases as the temperature decreases (goes below 90°F). On the contrary, temperature above 140°F kills microorganisms that play a vital role in decomposition.

So, if you are wondering if you can compost outside in chilly weather, simply check the temperature.

Moreover, starting a new composting process in winter is perfectly all right.

Helpful Tips for Winter Composting

Winter composting is different than summer and spring composting. It requires some effort to keep winter compost going at a reasonable rate. Here are some tips to help you get good quality compost in winter.

Materials to Compost and Avoid during Winter

Only add items in winter piles that compost quickly. Add kitchen scraps such as fruit and vegetable peels, cores, and rinds. Coffee grounds, eggshells, and paper filters are also okay for winter composting.

You must avoid materials like woody twigs and branches larger than ¼ inch must be shredded before adding. Moreover, wood ash must not be put in winter piles.

Read More: What Not to Put in a Compost Tumbler? [Complete List]

Harvest Finished Compost

Don’t forget to harvest the finished compost before starting a new pile in winter. Since the decomposition rate is slow in winter, the compost pile builds up quickly. Hence, it requires space, and you want your compost tumbler/bin to be empty for new composting.

You can also store the compost harvest in airtight bins at room temperature.

Gather Leaves

Leaves play an important role in winter composting. Gather some leaves in the fall and store them for winter composting. Leaves and pine needles are excellent browns and carbon-rich materials that help improve airflow and reduce odors. You can store leaves in bags or bins; cover the leaves with a tarp or plastic sheets if you use open bins. Covering helps avoid wetting and sticking.

Add Leaves and Yard Clippings

Scrape from your kitchen is always nutrient-rich, while the scrape from the yard perfectly balances the entire compost. You must add straws, plant debris, and leaves to your winter compost. Well-balanced compost with yard clippings will be helpful in springs to fertilize your garden.

Brown and Green Layers

Composting success depends on how well you layer greens and browns in winter and summer. Many people only add greens during winter, but it creates a stinky wet mess when spring arrives. You may not find brown during winter. So, it is okay to turn the pile in the spring and add more browns to improve drainage.

Another helpful tip for winter composting is to reduce the size of brown or green materials by chopping, cutting, or shredding. It provides more surface area for decomposers to break down the materials.

Track the Temperature and Insulate the Pile

The optimum temperature for composting is 90° and 140°F (32 – 60°C). The temperature will fall below 90°F during winter. You can use a long-probe thermometer, depending on how deep the pile is. These thermometers are available up to 4 feet.

Once you know the temperature, you can insulate the compost by various methods, such as surrounding it with bags of leaves or straw bales. You can also ring the bin inside with 6-12 inches of leaves, sawdust, or woodchips.

Let the Compost Sit (Don’t Turn the Pile)

There is no need to turn the pile in winter as it will result in heat loss from the interior. It will further slow the decomposition process.

Monitor Moisture

Many people ignore the moisture requirement while compositing in winter. You must ensure the winter compost piles have ample moisture for the microorganisms to survive and function optimally.

Also Read: How to Use a Spreader to Spread Compost?

Get the Right Ratio

A 30:1 is perfect for carbon and nitrogen in your compost pile in winters. Carbon is required for energy, and nitrogen is required for protein synthesis. This carbon to nitrogen ratio is ideal for microorganisms to break down the organic matter in the compost. So, try to put materials in your compost to help you achieve this ratio.

Add Some Worms

During winters, worm composting, also known as vermicomposting, is the best alternative to regular composting. Worms will turn organic matter into nutritive-rich compost with their activities. You can use a plastic storage container and PVC pipe for worm composting. Make sure to monitor temperature and moisture for vermi compost as worms need specific temperature and moisture to work.

Skip Wood Ashes or High pH Materials

Adding wood ashes to composting pile has more harmful effects than beneficial ones. Wood ashes in larger quantities can increase the pH of compost, and when the pH decreases from the optimum level, the activity of microbes will slow down. Most microbes work best at neutral to slightly acidic pH.

Special Compost Pile Site Design for Winter

Indoor composting, no doubt, is great in winter, but it is not fit for large-scale composting. People who compost a lot around the year can employ the following design map for open piles.

• Erect steel or fiber walls on the east, north, and west side of the pile. Leave the south open for maximum sun exposure.
• Dig 1-3 feet of soil and start your pile here; it helps keep compost insulated and active.
• If you live in an area with too much snowfall, you’ll have to shovel your path to the compost site (keep piles close if you have multiple piles). So keep them close to your backyard but not too close so that they look bad in the summer.

Frequently Asked Questions

Is it better to compost inside during the winter?

Inside composting during winter is better than outside composting because the temperature inside is higher. However, inside composting has its ups and downs. You can use a DIY compost bin, electric composter, or bokashi composting for internal composting during winter.

Is composting possible at freezing temperature?

You can compost in winters through food scraps in a compost bin or a tumbler. The composting rate will depend upon the temperature and moisture conditions for sure. You can insulate your tumbler and add worms to speed composting in winters.

How can I speed up composting in winter?

You can speed up the composting process by insulating the pile with the brown matter, a tarp, or surrounding it with bags of leaves.

What happens if you do not turn your compost pile?

If you don’t turn your compost pile and let it sit in the same place, decomposition will take 6-12 months. The exact time will depend upon the temperature and moisture conditions for sure. The cooler the surroundings, the more it will take time to decompose. Similarly, moisture also affects the microbial activity for decomposition.

However, it is better not to turn compost pile during winter as it can result in heat loss, and lower temperatures may kill the microorganisms.