Winter is when most things in the garden slow down, including the compost heap. As temperatures drop and days get shorter, the microbes that work to break down organic matter in compost are far less active than they are during summer.
Does this mean you can forget about your compost heap during winter and return to tending it in spring?
You can do plenty to manage your compost pile during the coldest months of the year. In fact, you can do several useful things to keep homemade compost active during the wintertime.
What Should You Do With Compost Over Winter?
During winter, you should add lots of green matter high in nitrogen to your compost heap. This will encourage microbial activity and keep the temperature higher. Only turn the pile two or three times a month and cover it with a tarp to keep it dry and insulated. Compost heaps should also be increased in size to keep the core warm.
Composting is a year-round project, and if you want good quality compost for your garden in spring, you need to put the effort in during winter.
Depending on where you live and how cold it gets during winter, you may face several challenges during the colder months:
- Windy, low-humidity conditions – Can cause your compost heap to dry out too much.
- Cold temperatures – Organic matter breaks down very slowly.
- Freezing temperatures – can turn your compost heap rock-solid.
To overcome these issues, you need to winterize your compost heap properly to prepare it for winter. This involves things like:
- Building a windbreak around the compost heap using bales of hay or straw if you have a windy location.
- Bulking up the size of the heap with leaves or other brown matter plus any green material you can find. A larger pile retains more heat and encourages decomposition.
- Cover the top of the compost heap with a tarp or burlap to keep it warm and dry.
- Adding loads of brown matter like fallen leaves or straw to the outer layers of the pile can help insulate the compost heap from the cold.
You also have to manage your compost heap slightly differently during the winter. You must take these steps to keep the microbes active and the decomposition process going:
- Regularly add lots of green matter, like manure, food and vegetable scraps, and coffee grounds. These things are high in nitrogen, so they feed the microbes, increasing microbial activity and helping to keep the compost warm.
- Chop up organic matter into small pieces before adding it to the heap. This speeds up the rate of decomposition.
- Turn the compost heap less frequently to prevent too much heat from escaping. Every 1 or 2 weeks is a good rhythm.
- Avoid adding wood ash to the heap, as it will quickly increase the pH outside the range that microbes can tolerate.
One of the biggest challenges during winter is finding green material. Most plants go dormant at this time of year. As a result, their metabolism slows down, and there is little or no new green vegetation. But winter compost piles actually need MORE nitrogen-rich material during winter. Regularly adding “green” organic matter each time you turn will help keep microbial activity working. So you need to look for alternative nitrogen-heavy ingredients to help keep compost active.
A few examples include:
- Coffee grounds. Try asking your local coffee shop for all their used coffee grounds.
- Food scraps. Aggressively stock your kitchen waste at this time of year. You can even ask neighbors to contribute.
- Waste pumpkins and winter squash. Jack-o-lanterns after Halloween are a great source of green waste. Again, ask your neighborhood to participate.
The size of your pile is also essential during wintertime. A bigger heap will retain more heat at its core so the decomposition process can continue to break down waste materials. Therefore, increase the size of your pile as much as possible. A five or six-foot diameter pile is ideal.
Now that you understand what to do with your compost heap just before and during the winter let’s discuss what you can do with the actual compost…
Does Compost Work In The Winter?
Experienced gardeners recommend spreading compost in the garden twice a year – right at the beginning of spring and late in the fall.
Does this mean compost doesn’t do anything for the plants and soil during the winter? Well, not exactly.
The reason it’s good to cover garden beds in a thick layer of compost during fall is that it gives the compost ample time to break down and release its goodness into the soil over winter.
But what if you’ve waited too long, and it’s already winter? Can you still add compost to the garden, or do you have to wait for spring?
Can You Add Compost To The Garden During Winter?
You can add compost to your garden beds and outdoor plants during winter. There’s no need to worry about it having any adverse effects on the plants or soil.
The only downside of covering the garden with compost at this time is that it has slightly less time to break down and release nutrients into the soil for spring.
If you spread compost in your garden during winter, it will still benefit the plants by:
- Insulating the soil and adding beneficial microbes.
- Slowly feeding the soil and improving the soil structure.
- Suppressing the growth of weeds.
- Preventing soil erosion if there is rain or snowmelt runoff.
- Acting like a mulch and improving the soil’s water-holding capacity.
How To Store Compost Over The Winter
Many experienced gardeners store their compost over the winter months. They dig all the finished compost out of the heap late in the fall, apply some of it to the garden, and then store the rest to use the following spring.
If you want to store your compost over the winter, it’s essential to stock it correctly.
The type of container you choose to store your compost in is not very important. The critical thing is that the container must have holes.
The microorganisms in the compost need air to breathe so that they can keep going about their business breaking down organic matter.
You can use old, empty pots, buckets, or plastic tubs with holes drilled in the sides, reusable fabric shopping bags, or even just plastic bags with some holes poked through them.
Fill up the containers with finished compost and store them in a cool, dry place like your garage, basement, or shed. It’s good to keep compost in a place where it won’t freeze, but if it does freeze, it’s not the end of the world.
Winter Compost Usage Tips
Your garden can benefit from compost no matter what season it is, so go ahead and cover your beds with it during winter!
Here are some expert tips from veteran gardeners on using compost during the winter:
- Add a 1 or 2-inch-thick layer of compost to your garden beds and around trees and shrubs.
- Avoid the compost touching the stems of plants, especially those with herbaceous (non-woody) stems. Leave a little ring around the stems.
- Don’t dig compost into the soil during winter. Disturbing the earth harms the microorganisms living in it. They have a far more difficult time recovering in winter when it’s cold.
- Your compost may get soggy from rain or snowmelt at the beginning of spring. To prevent it from getting smelly, add lots of brown matter, like wood chips, sawdust, or dry leaves.
Should I Add Compost Before Winter?
It is best to add compost to your garden beds and potted plants before winter. Doing so gives the compost a whole season to break down and release nutrients into the soil. That said, late in the fall is one of many times you can use compost. It’s totally okay to spread it during winter or in the spring.
Should I Turn My Compost Heap In The Winter?
Turning a compost heap during winter causes it to lose a lot of heat and slows the decomposition process. Therefore, you should keep turning to a minimum in the winter months.
What Do You Do With Compost After Winter?
After winter, try to add lots of carbon-rich brown matter to your compost heap. This is especially important if your compost heap has frozen over winter. Compost heaps are often very wet and soggy from the post-winter thaw and can get smelly if there aren’t enough dry leaves, sawdust, wood chips, or straw. Turn the pile well to improve aeration.