A compost pile is undeniably a great thing to make for your garden and other planting activities. A rich mixture of broken-down biomatter can supercharge your soil with tons of nutrients that plants need.
However, there are plenty of people who have hesitated prior to installing their own compost pile after hearing stories of the reeking stench they emit.
It’s a fair concern, as no one wants their home smelling like a garbage dump. So does compost smell bad?
Yes, compost can sometimes smell. Compost will often stink before it is broken down, and improperly managed compost piles will always smell terrible.
Know that once the composting process is underway and the microbes have had a chance to do their work, the odor should go away.
If your compost pile still smells bad after a few weeks, it means that something has gone wrong and you should take steps to fix it. We’ll tell you all about it below.
A Properly Balanced Compost Pile Smells Like Dirt
A compost pile that has been properly balanced, maintained, and given enough time to break down won’t stink. Instead, it will just smell like what it is: dirt!
Bad Smells Mean Might Mean Something is Off
There are several reasons why your compost might smell bad. Pretty much all of them have to do with the pile not being properly managed.
When the items you add to the pile are allowed to rot and just sit there without being acted on by the bugs and microbes that should be living in your pile, they’ll start to smell bad. And they’ll stay that way!
The same goes for when the pile isn’t turned and refreshed with new oxygen-rich biomatter. The lack of movement will cause anaerobic bacteria to form, and they’ll produce some pretty rank smells.
Additionally, if your compost is too wet it can also lead to bad smells.
This is because standing water prevents the aerobic bacteria from doing their job and instead lets anaerobic bacteria take over once more, aside from fomenting the formation of mold which also smells terrible.
We’ll dig into all of these likely problems below.
Too Much Greenery Will Cause Your Compost to Reek
The most common reason is that the ratio of green to brown materials is off, and there is too much green matter in the pile.
Green matter includes things like grass clippings, fruit and vegetable scraps, and other fresh plant matter. Brown matter includes things like dead leaves, twigs, and dry grass. Easy to remember!
The key to a good compost pile is to have about 3 parts brown matter to 1 part green matter. This ratio will provide the perfect mix of carbon and nitrogen that your microbes need to thrive.
If there is too much green matter, it will start to rot and smell bad before the composting process can really get underway.
If your balance is off, that’s okay. Just fix it and turn that pile.
Too Little Air Can Do the Same
Another common reason for smelly compost is a lack of oxygen. The microbes that do all the good work in your compost pile need oxygen to live, and if they don’t have it they’ll start to die off.
This will lead to another kind of bacteria taking over, anaerobic bacteria, which smell bad and can actually delay the progress of your compost pile.
The solution is simple: just turn your pile more frequently to introduce more oxygen. You should be doing this anyway, as turning the pile speeds up the composting process by aerating it.
But if you’re not turning it enough, or if it’s too densely packed, then that could be the source of the stink.
Break it up, spike it, turn it- anything you can to keep the oxygen moving through it!
Too Much Water Can Also Make It Smell
If your compost is too wet, it can also lead to bad smells and is a common problem in the wet season wherever you live.
This is because standing water once again prevents the aerobic bacteria from doing their job and instead lets anaerobic bacteria thrive.
Not only that, but excess moisture will also foster the growth of mold which smells a bit rank, as mentioned.
The solution is to make sure your compost pile has good drainage and isn’t too soaked. If it’s too wet, you can add some dry brown matter like dead leaves or straw to help soak up the excess moisture.
You can also build your compost pile on a raised platform to improve drainage. Just make sure the platform has holes to allow for both good drainage and airflow.
Manure Will Always Smell Until Totally Broken Down
Sometimes, the “ingredients” in your compost pile will just smell awful for a time. This is especially true of manure, which both stinks horrendously and can take a long time to break down fully.
If you have added manure recently, just give it some time and the smell will dissipate as the manure breaks down further.
Alternatively, you can add a straw, hay, newspaper or similar material overtop of it to help block the stink. But, as mentioned, you should be prepared for and expect a gross aroma for a time!
Counter Nasty Compost Odors with Corrective Measures
In short, if your compost smells bad it’s because something has gone wrong in the process. It’s too wet, there’s not enough airflow, or there’s too much green matter.
But whatever the case, you can fight those odors in the meantime by taking the right steps.
Tom has built and remodeled homes, generated his own electricity, grown his own food and more, all in quest of remaining as independent of society as possible. Now he shares his experiences and hard-earned lessons with readers around the country.