The beautiful thing about compost is that you don’t really have to babysit it all that much.
So long as you set your compost pile up right from the get go it only takes a little bit of regular “feeding” and turning on your part to transform organic waste into super fuel for your plants and garden.
It’s hard to imagine any more “set it and forget it” than compost – at least until colder weather rolls around, anyway.
As soon as the mercury starts to dip your compost is going to need a bit of attention.
You’re going to want to insulate your compost bin ASAP ahead of the frost and freezing temperatures, protecting all that you have built up inside of your compost box so that you don’t have to start from scratch all over again in the springtime.
Of course, not everyone knows how to insulate a compost box – or why it is so mission in the first place.
That’s why we have put together this detailed guide, though.
Let’s dig right in, shall we?
Why You Need to Insulate Your Compost Bin in the First Place
A compost pile might not look like much more than a hump of organic garbage in a compost box or compost bin, but underneath the top layers is a living, breathing ecosystem that requires some very specific parameters to continue turning your waste into plant fuel.
We’re not just talking about the worms and other bugs that live inside of your compost bin, either (though they are going to appreciate a bit of extra insulation when colder temperatures show up, too).
No, we are talking about the bacteria and microbes that do the bulk of the heavy lifting when it comes to transforming your organic materials into super rich, super nutrient dense biomaterial that can supercharge your plants, your fruits, and your vegetables like nothing else.
By insulating your compost bin and buffering those living, breathing organisms and biomes you are protecting them from the devastating impact of freezing and subfreezing temperatures.
Sure, your compost box might go slightly dormant as the mercury drops.
But with a bit of insulation you aren’t going to kill off everything that was living inside of your compost pile, necessitating that start from scratch in the springtime we mentioned a bit earlier.
If you’re serious about keeping your compost box rolling all year round, insulating it from cold weather is a huge piece of the puzzle.
5 Easy Ways to Insulate a Compost Bin
You have a lot of different options available to help you insulate and protect your compost from the damage of colder temperatures, but the five options we highlight below aren’t just super easy to implement – they are also very inexpensive (if not completely and totally free).
Let’s get into it.
Cover the Compost Itself
The easiest way of all to insulate your compost bin is to simply cover it, trapping in the heat caused by the chemical reactions of the composted materials getting broken down in the first place.
Covered bins and boxes are incredibly popular for this exact reason.
A lid traps a lot of extra heat (and even a bit of extra humidity) to better regulate the composting process while keeping out colder temperatures, rain, and other environmental conditions that could wreck your compost process completely.
If you really want to take things to the next level you could always “double box” your compost with a lid inside of a lid.
This extra step seals things down, working a lot like a two exterior door system does on homes and other buildings.
The outermost lid protects from outside attacks (wind and weather) while the innermost lid really works to insulate and trap warm air and moisture inside.
Build a Little Compost Bin Tent
Compost bin or box “tents” are another way to go when you’re looking to add a little bit of extra protection and insulation for your actual compost pile.
The overwhelming majority of people that go in this direction first lay down a bit of straw or hay on top of the compost bin, locking in that heat and building up a layer of natural insulation.
After that, a tarpaulin or solid wood/plastic/metal tent goes up over the compost box to keep wind and weather (rain and snow) off of the insulative layer and the compost underneath.
A huge advantage here (especially if you use natural insulation like straw or hay, or even woodchips) is that the insulative material inevitably gets folded into the compost itself.
Not only does that protect your compost environment over the colder months, but it also prevents you from having to clean things up in the springtime.
Simply roll those natural materials into your compost pile and you are good to go!
Bury Your Compost for the Winter Months
If you are willing to let your compost pile really sort of slow things down, going almost dormant over the winter months, it might not be a bad idea to dig a hole below the frost line and bury your compost over the winter.
The hitch here is that you aren’t going to have access to your compost until the spring – but if you live in cold enough climates where you have to dig below the frost line to protect your compost that’s not going to be an issue.
It’s not like you would be planting new seasons of crops in the middle of a snowstorm!
By digging beneath the frost line and then bearing your compost you allow it to avoid the damage that super low temperatures can cause while allowing the composting systems to rest, reset, and sort of recover.
In the spring, dig everything up and allow it to warm again and you’ll be able to pick right up where you left off in the fall or early winter.
Bring Your Compost Up Off the Ground
Raising your compost pile in the bin or box you’ve been building it in is mission-critical when you need to insulated from cold temperatures.
Nothing is going to steal heat from your compost pile faster than cold ground temperatures, absorbing all the heat that your worms and aerobic microbes are producing during the actual compost process.
By raising your compost up off of the ground – separating it from those frigid temperatures and heatsinks – you’re able to eliminate that heat theft altogether.
A lot of people do this by piling their compost into what’s called a “compost tumbler”.
It looks a lot like a cement tumbler (and operates similarly as well), though this specific piece of hardware is engineered to keep your compost pile aerated while slowly spinning it at a consistent pace.
You’ll be removing your compost from it’s bin to add it into a tumbler, but you don’t have to do this on a permanent basis.
All you have to do is get through the colder weather with your compost safely squirreled away up off the ground and you can dump it all back under the ground in the spring without skipping a beat.
Use Insulated Compost Bins
This is a super easy way to insulate your compost bin, though it does require a little bit of foresight on your behalf.
After all, dumping out a compost bin onto the ground just to insulated after-the-fact – and then fill it back up with your compost afterwards – is not the smartest approach to take.
Insulated compost bins look a lot like gigantic coolers and operate on the same basic principle.
The idea here is to trap all of the heat generated by the composting process inside your compost box that has been insulated with (usually) foam or rotomolded plastic walls.
If you really want to take things to the next level you could even build your own insulated compost bins for winter purposes.
Old ice boxes work wonders in this department, as do chest freezers that don’t work anymore but still have insulated walls and doors that are intact.
It’s Important to Check the Temps of Your Compost Pile Regularly
At the end of the day, no matter how you choose to insulate your compost bin or compost box, it’s a good idea to have a method to track the temperatures of your compost throughout the year all the same.
As a general rule, you want the very middle of your compost pile to be between 90°F and 160°F (if not a little warmer) as close to all your round as possible.
Temperatures that drop any lower than 60°F will slow down the production of your composting bacteria, and temperatures that go below 40°F will kill bacteria, microbes, and your worms – stopping the composting process completely.
There are composter monitors out there that are 20 inches long (or longer) to help you read these kinds of temps, and you’ll want to get your hands on one ASAP.
You can also rig up a system using traditional thermometers, digital readout thermometers, and even IR contactless thermometers – what you really need something that can penetrate down into the lower levels of the compost pile to know exactly what is going on.
Reading surface temperatures will give you some info, but those outer layers are always going to be running cooler than the middle layers where the most activity is going on.
Make a commitment to check the center temps on your compost box every two weeks or so – including throughout the colder months when you have everything insulated – just to make sure that you are staying on track.
If things start to deviate and your compost box starts to get cold you might need to ramp up some of the steps we highlighted above to get those temps back into the “Goldilocks Zone” ASAP!