Winter Composting

Aside from having a specific ‘Winter Composting’ category on the blog, I decided it might be helpful to create a winter composting resource page so people can A) learn more about winter composting in general, and B) access all the pertinent blog posts I’ve written (here and elsewhere), along with other useful tidbits (videos, photos etc). I’m going to keep things relatively simple for now, but will definitely continue to build this page over time.

What Is Winter Composting and Why Should You Do It?

Let’s start by defining the term ‘winter composting’. Obviously we are talking about ‘composting in the winter’ here, but I think it’s important to point out that when I say ‘winter’, I’m referring to the real deal - the often-harsh, snowy, freezing winters encountered in Canada and the northern states (along with many other regions of the world). To be totally honest, my location in Southern Ontario (Canada) is somewhat tame in comparison to many regions of the ‘Great White North’ (and even Northern USA), but I have little doubt that outdoor winter composting can take place in much colder regions as well, with a little bit of extra effort.

Now that you know what I’m referring to when I talking about ‘winter composting’, you may still be wondering WHY?!?
I imagine the very notion of winter composting must seem a little extreme, or ridiculous…or perhaps even extremely ridiculous to some people (my neighbours, for example)!

After all, why on earth would anyone want to trek outside in sub-zero weather to add kitchen scraps to their compost bin when their gardens are frozen solid and there are other indoor methods, such as bokashi or vermicomposting, that can be employed to deal with waste materials during the long winter months.

Good question!

Here are some possible reasons for keeping an outdoor compost bin active all winter long:

• Helpful if you need (or simply want) to deal with large quantities of waste materials - more than can be handled by a typical indoor home-based system
• Many people probably don’t want to maintain indoor systems, for a variety of possible reasons
• It can be a really fun challenge, and a great way to master your composting skills in general
• Great way to get some attention (not all good perhaps - haha), and thus a good way to educate others about composting
• Relating to the previous, a winter compost bin can make a great conversation piece
• Depending on the techniques used, it could actually provide a supplemental heat source for a winter greenhouse (would require larger composting mass than the one in my system)
• You won’t likely need to worry about the system drying out or overheating (as can happen in the summer)

These are just a few of the possible reasons for giving winter composting a try!

Basic Requirements for Winter Composting

Heat Source
In order to compost successfuly all winter long you need to make sure that your system stays microbially active. A frozen heap, or even one with temperatures just above the freezing mark won’t do you much good. Keeping a system warm and microbially active will require the presence of an external heat source or enough material (’critical mass’) - with a well balanced C:N ratio ( somewhere between 20:1 and 40:1 will work best) - to support microbial heating. The critical mass for thermophilic composting is generally in the range of 1 cubic yard - so you will definitely want to use a system that has a volume of at least that much (the colder your region, the bigger you’ll likely want to make your system).

Insulation
Unless you are creating massive winter composting heaps (a lot bigger than 1 cubic yard), you will likely also need to insulate your system somehow. An excellent low-tech approach would be to simply stack up straw bales around the outside of your bin. In fact, you could make an excellent winter system by simply stacking straw bales (to create the walls), then filling it with your balanced mixture of waste materials.

To create my current insulation system I first lined the inside of my bin with multiple layers of corrugated cardboard, then built an outer wall around my bin, thereby creating a space I could stuff full of insulation (in my case, second-hand home insulation). I then added some additional layers of cardboard between the outer wall and the insulation layer.

In areas where heavy snowfall occurs, snow can obviously be used as a great supplemental layer of insulation - I have big heaps of snow adjacent to 3 of the 4 faces of my bin. Another great naturally occurring source of insulation is the earth itself. Digging a compost pit in the ground, or better yet into the side of a hill can be an easy (and effective) strategy.

Apart from having insulation around the outside of your bin, it will also help to maintain a thick layer of bedding over top of your composting mass. Loose straw and fall leaves are very well suited for this task, but there are plenty of other possibilities as well.

“Fuel”
To keep your system chugging along all winter, it will certainly help to continually add fresh waste materials. I recommend keeping a bucket (or larger container) for all your kitchen scraps to ensure that you are adding a decent amount each time you make a trip to the bin. You may even want to seek out external waste sources just to make sure you have enough. Local coffee shops (for coffee grounds), grocery stores (for waste produce) or stables (for manure) are just a few possibilities.

Winter Composting Posts from 2007/2008 (Compost Guy Blog) (in chronological order)

Winter Composting Extravaganza II
Oh, The Weather Outside is Frightful!
New Years Composting
Ask and Ye Shall Receive
Windy, Warm…Now Wintry!
The Real Challenge Begins!
Wacky Weather Continues
More Snow, More Cold - What Else is New?
Winter Composting Wrap-Up

If you have Flash installed, you may want to watch the full (longer + high resolution) version on the Red Worm Composting website. Access the page >>HERE<< (again, remember you will be leaving this site)

Winter Composting Extravaganza
Composter’s Log - Stardate 60352.8
Composter’s Log: Stardate 60376.9 - RED ALERT!!
Composter’s Log: Stardate 60393.6 - Winter Has Arrived
Composter’s Log: Stardate 60429.3 - Unusual Life Forms
Composter’s Log: Stardate 60492.2 - ‘Oh Winter, Where Art Thou?’
Composter’s Log - The Iceman Cameth
Composter’s Log - Dontchu Know I’m Loco?!
Composter’s Log: Letting Sleeping Mice Lie
Composter’s Log - Back In Business!