So, you started your first compost pile in spring. And after some experimenting, you’re helping it break down your organic wastes at a healthy rate (well done!). But now it’s getting cooler, and you’re worried about what will happen to your thriving compost pile in the winter.
Good news: You don’t need to put a freeze on composting as the temperatures drop! You can get nature recycling in your garden yearlong.
Keep scrolling for my winter composting guide, packed with tips and advice to keep you composting successfully throughout the chilly months.
How To Compost In The Winter
Composting basics stay the same, no matter the season. Whether the weather is hot or cold, composting microorganisms need a balance of nitrogen and carbon-rich organic wastes, moisture, and air to stay healthy. Protecting your compost against snow and rain can help with wintertime composting.
Maintaining a compost pile in the winter isn’t drastically different from composting in any other season. Still, wintertime composting comes with extra challenges (besides having to brave the icy weather to visit your compost!)
But don’t get cold feet about composting! There’s a way around every problem.
Let’s look at the mistakes to avoid when tackling composting outdoors in the cold…
Can You Compost During The Cold Winter Months?
Yes it is possible to compost during the winter. However, don’t expect the process to be as fast as in the warm months. Cold temperatures will slow down decomposition.
If you have organic waste, you can compost it. Period. Come rain, wind, cold, or snow, you can make it happen!
If you’re a winter composting newbie, make it your goal to keep your composting microorganisms (like bacteria and fungi) alive and working, however slowly.
Winter Composting Essentials
Aerobic (with oxygen) composting microorganisms can endure the cold but can’t live without food, air, and water.
Here are 3 ways to care for the helpful little creatures breaking down everything in your compost pile, whatever the season:
- Feed them a good mix of greens (organic wastes high in nitrogen like fruit and veggie scraps and coffee grounds) and browns (dried leaves, shredded paper, ripped cardboard egg boxes, and other carbon-rich organic wastes).
- Keep air flowing through the compost.
- Stop the compost from getting too wet or dry.
Okay, you’ve got the survival basics covered. Now you can focus on making winter more pleasant for your composting team.
Here are my top tips for helping your microorganisms get through the cold months:
- Build a biggish pile. Aim to make your pile at least 3x3x3 feet. But don’t get carried away! Keep it to 5x5x5 feet max. A pile that’s too small won’t hold on to heat, and a pile that’s too big might become waterlogged and starved of air in the middle (it’s also a mission to turn).
- Shred to Boost the breakdown. Cut, chop, rip or shred organic wastes before adding them to the pile so composting creatures don’t have to work quite as hard to break them down. I keep most pieces to an inch or smaller but throw in a whole twig, pinecone, or corn cob now and then to help air circulate.
- Keep the pile warm. Does it get super-chilly with icy winds where you live? Then you’ll need to protect your compost pile by surrounding it with bales of straw or hay or bags filled with leaves. My trick is to throw a waterproof tarp over the top 2/3 of my pile for extra protection against the cold, rain, and snow. Pick one in a dark color to soak up the sun. (Amazon)
What Happens To Compost During Winter?
A compost pile with microorganisms happily working away in the warm seasons will continue breaking down in the winter.
The major difference between summer and winter composting is that winter compost generally doesn’t heat up as much, making it a slower process.
The microorganisms can’t raise the compost temperature as high as they can when the air temperature is hot. And cooler compost is sluggish. I get it; I’m also slower in winter!
Steam coming from the compost is a sign that your composting team is alive and well. Another way to check that the microorganisms are healthy is to stick a gloved hand into the middle of the pile. If it’s warm, it’s all good!
Can You Keep Adding To Compost During The Winter?
You’re free to keep tossing your food scraps and garden waste onto your compost pile throughout the winter. In fact, you should if you want to keep your microorganisms alive!
Getting your organic waste’s green-to-brown ratio right is especially important in winter. The ideal pile is about 1/3 greens to 2/3 browns. So, throw in 2 parts brown for every part green you add. This ratio will help composting creatures keep going even when it’s “brrr…” outside.
Tip! Start collecting dry leaves in the fall to have a stash of browns when you need them.
Check out my easy guide to the ideal brown-to-green compost ratio for more tips for getting a perfect balance.
You should, however, keep some types of organic waste out of slow winter compost. These are the main no-nos:
- Wood ash can increase compost’s pH, making decomposition difficult for microorganisms.
- Pine and juniper needles take forever to break down (thanks to the resins they contain), further slowing down winter composting.
- Animal products (like meat, fish, and dairy), oils, and fats also take a very long time to decompose and create a stink as they rot.
- Pet poop can contain bad bacteria that cooler winter compost piles can’t kill.
- Weeds and weed seeds can survive the lower temperatures of winter compost piles (and spread around your garden).
How Often To Turn Compost During The Winter
Winter piles need a lot less mixing than summer piles. Turning your pile every month or so should do it! More than this can let too much heat escape from your compost’s toasty center.
So you can take it easy with turning your compost in winter.
Warning! Don’t turn your compost in the middle of winter or on especially icy days.
Should You Water Compost In Winter?
Compost should always be moist.
Check your compost’s water level regularly by reaching in, grabbing handfuls around the pile, and squeezing. Compost is known to decompose quicker when the core temperature and moisture levels are increased.
Suppose water drips out when you squeeze. Your compost is too wet and needs a few shovelfuls of absorbent browns mixed in. If your compost feels a bit dry, sprinkle water until it’s moist. You’re aiming for a moisture level that feels like a wrung-out sponge.
Tip! Save yourself trips to your compost pile by checking its water level when you turn it. I also cut down the number of times I need to go to the pile by storing daily food scraps in a closed bucket in my kitchen and then dumping them in the compost when the bucket is full.
How To Activate Compost During The Winter
If balancing greens and browns and keeping your compost moist and airy doesn’t get the decomposition going, you could add a compost activator to the pile to move things along.
You can buy artificial activators, but I suggest you use a natural one like this. (Amazon)
Alternatively, my all-time favorite activator is a shovelful of finished compost or topsoil. Other natural options that get my vote are bone, blood, soy, or alfalfa meals.
Check out more tips for speeding up winter composting.
How To Use A Compost Bin In Winter
You say you’ve got a compost bin, not a pile. No problem! All the guidelines I’ve shared work for bins, too.
I’ve got 2 special guidelines for everyone composting in a bin:
- Harvest any finished compost from your bin at the end of fall to make space for your winter waste. Here are suggestions for what to do with compost in winter.
- Line the inside of your bin with about 10 inches of leaves, sawdust, or woodchips to help contain heat.
Should I Leave My Compost Bin Outdoors In Winter?
You don’t need to bring your compost bin indoors in winter. So, stop rearranging furniture in your guest bedroom!
Compost can get too hot indoors, so hot that it could catch fire! So, leave your bin where it is.
What About Using A Compost Tumbler In The Winter?
A compost tumbler can be just right for winter composting. It’s easy to turn and can speed up results. But only if it’s well-insulated to keep the compost temperatures up!
One of the best-known insulated tumblers is the Mantis back porch ComposTumbler (Amazon)
No, that’s not a typo 🙂