8 Quick Ways to Fix Your Smelly Compost

We’ve talked about it a lot here on New Life on a Homestead: compost is one of the very best things you can possibly use in your garden, your raised beds, your containers, and anywhere else you happen to be planting. All-natural and packed with nutrients that plants need, it’s easy and cheap to make your own rich compost at home with very little effort.

But sometimes, when things go wrong, your compost bin or pile can start to stink. And worse than stink, it can start to reek!

Contrary to what most newbies think, compost shouldn’t stink—or at the very least, it shouldn’t stink very badly or for very long until the process gets underway. But when your bin isn’t breaking down like it should or hasn’t been properly managed, you could be facing some ferociously nasty odors.

It’s enough to drive anybody crazy, and it can put a strain on your relationship with your spouse or your neighbors. But you don’t need to bag everything up and just throw it out: a smelly bin is often easily fixed. Keep reading, and I’ll tell you about some really easy ways to do it.

Before You Act, ID the Odor

If your nose crinkles when you walk near your compost bin, the temptation will be there to go through the following fixes rapid-fire. Believe me, I get it!

But that might waste time, effort, and end up doing more harm than good if you aren’t careful. As gross as it is, take a moment to identify the nature of the stink. That will help to tell you what the problem is. Check out the following and keep it in mind as you read the fixes below.

• Sickly Sweet: A sickly sweet odor is a surefire sign that you’ve got too many greens, or nitrogen-rich components, in your pile. This is an imbalance you should correct.
• Foul/Like a Dumpster: Despite being made up partially of garbage, your compost pile shouldn’t smell like garbage. If it does, you’ve left some things on the surface to rot.
• Rotten Eggs: The worst possible smell to be coming from your compost pile. A nasty rotten egg or fecal smell is invariably caused by the proliferation of anaerobic bacteria. The pile might not be getting enough oxygen or is too wet.
• Urine/Ammonia: If the compost has an odor more like a truck stop bathroom, that’s another indicator that there might be too much nitrogen in there, meaning too many greens.
• Moldy: A moldy smell like a forest floor, crawl space, or water-damaged house is normal unless it is very strong. If it is, you might have too much carbon-based material in the pile.

8 Fixes for Smelly Compost

✓ Aerate Thoroughly and Often

This is one of the very best fixes for a stinky compost pile of any kind, and especially one that smells like rotten eggs or a sewer.

Turning your pile is critical because it will promote oxygenation, a process called aeration. This, in turn, will support the oxygen-craving bacteria that we want to break down the items in the pile.

They are faster, do a better job, and stink far, far less than their cousins. If there’s not enough air, anaerobic bacteria will take over, and they are the ones that cause problems.

Luckily, turning your pile is easy with a pitchfork, shovel, spade, or specialty compost aerator. In a pinch, you can just poke holes in the pile using a long, sturdy stick or broom handle.

As a rule of thumb, turn your pile or otherwise aerate it no less than once a week and preferably once every 3 or 4 days. It makes a big difference in performance and speed of decomposition!

✓ Turn Stinky Food Scraps Well Under the Pile

Like I mentioned above, your compost pile should not smell like a garbage can. Or at least, it shouldn’t smell that way for long.

Whatever kind of kitchen scraps you are adding, if you leave them sitting on top they will just sit there and rot out in the open, and that means they will smell like a dumpster in very short order, especially if you live in a hot and humid environment.

This is awful not only because it stinks, but because it is a surefire way to attract rodents and raccoons. You don’t want that.

Luckily, the fix is easy: simply turn these items well under the pile. Not a few inches, not covered with a scant scattering of leaves—bury them. That way you won’t have to smell them while they are breaking down.

✓ Consider Throwing Out Nasty Additions

There are some things that you genuinely just shouldn’t try to compost. Not to say that they aren’t compostable in the end, but these things take a lot longer to break down and stink a whole lot worse while they do…

I’m talking about things like beef or chicken, any kind of animal bones, and, worst of all in my mind, fish and fish guts. Animal poop, too, is not something I will add to my compost pile unless it’s already well-rotted manure.

These things are ferociously stinky, and if they get added to your pile deliberately or accidentally, consider just throwing them away instead to save yourself the aggravation.

✓ Dry It Out if Too Wet

Keeping your compost moist is critical for a steady decomposition, but if you haven’t protected the bin from rain or if you get a little too zealous with the water hose, you might saturate the pile.

This in turn will often cause that nasty rotten egg odor we’ve talked about already. This doesn’t mean that your compost is ruined and you should just bag it up and throw it out; all you need to do is help dry the pile out.

This can be done by maximizing airflow and spreading it out in a thin layer temporarily. A good solution is to add sawdust (from non-pressure-treated wood!) or finely shredded paper. This stuff will soak up the water, equalizing moisture levels and then quickly breaking down itself.

I like to keep a big container of sawdust nearby in the shed for just such an occasion.

✓ Rebalance Green and Brown Material

A gross, sweet odor or a distinctly urine-like ammonia smell is an indicator that your pile has too many greens and not enough browns.

This is another mistake that’s very easy to make, especially if folks are getting a bit too liberal with the kitchen scraps. Happily, the fix is really easy and accomplished by adding more browns to balance this out.

Inversely, if you notice a distinctly musty, moldy odor coming from your compost bin, it’s likely you’ve added too much carbon-rich material, that is to say, browns.

Give it a good turn, add some greens (but not too many!), then stir it again and the smell should start to dissipate in just a few days.

✓ Add a Layer or Two of Straw

Sometimes, despite your best efforts, your compost will just be a bit stinky and either these other fixes weren’t effective or, simply enough, nothing is wrong with your pile in the first place.

Whatever the reason, if the odor is bothering you and you want to nip it in the bud right now without unduly affecting the balance of the pile or the decomposition process, reach for straw.

Not only will straw break down in time on its own and contribute to the compost, but it won’t significantly alter the existing balance. What it will do, though, is act as a natural filter that will dampen down the odor.

The best way to use straw is to pull back the upper half of your pile and then layer a mat of straw in the middle. Pull the compost back and then put another layer on top, but loosely; you don’t want to cut off airflow.

It takes just a few minutes and will dramatically improve the odor situation.

✓ “Cut” Processing Compost with Finished Compost

Here’s a genius trick that I learned from my great-grandpa. If you are producing your own compost in batches, and you really should be, take a little bit of finished compost from the oldest one and use that to tamp down the odor in one that is processing.

Sounds a bit strange, but it really works, and more than that, it will also supercharge the decomposition process. All you need to do is mix it in: however big your existing pile is, consider adding anywhere from 5% to 10% finished compost by volume and that should do the trick.

✓ Try Natural Odor Absorbers

This is another quick and dirty method that can squash odors without halting the composting process or wasting all of your hard work you’ve already put in.

Some materials that are good for your pile also happen to have natural odor-fighting properties, and if you’ve been struggling with a truly stinky bin these things are your best friends.

Reach for biochar, hardwood ash, or zeolite. These things will bulk up the compost in addition to cutting down the odor significantly, and best of all, they work instantly.

If you have a layer in your pile or bin that is slimy and gross, generously sprinkle this stuff on top before turning the pile thoroughly. If the whole pile is a little smelly, sprinkle some on top and mix it in, then mix in a little more as you go.