Will My Compost Smell? How Bad Will it Be?

Whatever kind of planting and gardening you’re doing around your home, one of the best resources in your arsenal is a large, properly maintained compost pile.

compost pile
compost pile

Aside from reducing waste, composting allows you to supercharge your plants with tons of nutrition that they desperately need.

Plenty of beginning gardeners want to start a compost pile but might feel a little intimidated. A big part of this intimidation is worry over bad odors.

If you have a decomposing pile of food scraps, vegetation, and more in your backyard it’s probably going to stink, right? Won’t it? Just how bad will your compost smell?

Your compost pile won’t smell bad if properly maintained. Some items you add can stink for a while, however, and problems with the pile can lead to nasty, foul odors.

It’s true. It seems almost impossible that a pile of decomposing organic matter won’t smell terrible, but once the process of decomposition is complete all you’re going to have is dirt, and dirt just smells like, well, dirt.

You might have to put up with some unpleasant odors while the compost pile is decomposing, or processing, though and there’s no way around the fact that some things you’re going to add to it smell pretty gross at the time.

Keep reading and I will tell you everything you need to know about odors you can expect from your compost pile and what you can do about it.

Compost that Has Completed Decomposition Won’t Smell Bad

A compost pile is so named because it is undergoing a process, a process of decomposition.

All of the things that you put in your pile, from food scraps and wood to green vegetation, manure, paper and more all break down over time.

Eventually, they will all break down into rich, dark soil but it’s perfect for new plantings and for feeding plants that are already established.

When the contents of your pile reach this stage, they won’t really smell at all anymore. It will just smell like dirt, sort of like the slightly moist, mineral odor of a forest floor.

Now, this is not to say you won’t experience some truly nasty odors from your compost pile at various times, or when things go wrong.

Knowing what to expect and whether or not you should deal with it is important if you want a productive and healthy compost pile.

Getting to “Odor Neutral” Takes a Little Time

One thing to keep in mind is that creating compost takes time, and it might stink until it is fully processed.

Microscopic life, insects, worms, and other tiny creatures will eat, live on and reproduce in your compost pile, breaking it down slowly over time.

Even when they’re doing their jobs, healthy and happy, this takes time during which the contents of the pile might stink.

Things like manure, old food scraps, musty vegetation, and things like that can be great additions to your pile but none of them smell good.

If you are near your pile, you’ll probably smell these things, even if you’ve buried them, turn them regularly, and so on.

Understand that and accept it, but your compost pile should never truly be a hideous heap of garbage. If it is, something’s gone wrong.

If Your Compost Pile Smells Bad Persistently, Something’s Wrong

There are several things that can go wrong with your compost pile, slowing or even halting the decomposition process, and typically promoting some seriously nasty odors.

This is because so much of the process depends on organisms that need oxygen, and they won’t be able to get it if you aren’t turning your pile or if it gets too wet (either from over-watering it, or from it getting soaked with rain).

Look at each of the following factors, and try to narrow them down to determine if your smelly compost pile has been afflicted by one or more of them.

A Lack of Oxygen Can Lead to Smelly Compost

This is one of the biggest and thankfully also the simplest problems that might afflict your compost pile.

As mentioned just above, all the microscopic life and other tiny organisms that we depend on to process our compost are aerobic in nature, meaning they need air in order to live and work.

If they can’t get this air, they stop working or even die off, and that will let anaerobic bacteria and organisms take over. It’s this factor that so often leads to some seriously nasty odors.

Luckily, the solution is as simple as it gets. All you need to do is turn, mix, and otherwise aerate your compost pile more often.

Not only will this introduce more oxygen into the pile to keep things underway, but it will ensure a more even mix of ingredients and better, quicker decomposition overall.

Too Much Moisture Causes Excess Mold Growth

Moisture is another thing that our compost pile needs, but it doesn’t need it too much. Too much moisture is a harmful one to punch for our compost pile.

It can smother the tiny organisms we just discussed, preventing them from getting oxygen that they need to live, and it can also promote mold and fungal outbreaks which will increase odor and slow down good decomposition.

This is a common problem if you leave your compost pile uncovered and are dealing with rainy weather, and sometimes beginning composters make the mistake of over-watering the pile with their hose or watering can.

This, too, can be dealt with by protecting the pile with a lid or tarp, keeping it out of flood-prone areas of your property, and adding more dry materials to help soak up and redistribute water.

Too Many Greens Can Cause a Stink

If you’ve done even a cursory amount of reading on managing a compost pile, you know that it is composed of what is commonly referred to as greens and browns.

This refers to the type of organic matter going into the pile, with browns being things like dead leaves, twigs, dry grass, and greens being fruit, vegetables, fresh grass clippings, and so forth.

But if you add too many greens you’re going to be facing a problem with rot because it will stick around and decompose the ugly way instead of the proper way in the pile and that can lead to a truly nasty compost pile.

Your exact ratio of browns to greens will vary somewhat depending on the specific contents of the pile and other factors, but you usually want it to be 3:1, browns to greens.

If your ratio has way too many greens in it, you don’t need to sweat it: just add more browns, and carry on.

Consider Moving Your Pile If It’s Too Smelly

Let’s face it: though you won’t have to put up with a smelly compost pile forever if you’re doing your part they don’t ever smell good, and they won’t even smell neutral for a little while until decomposition is well underway.

If offensive odors are getting you down or aggravating your family members, consider moving the pile.

Getting it away from your house is always a good idea even if it is less convenient, and it is possible to place it in an area where the prevailing winds will typically carry the smells away from your home or outdoor space.

Also, don’t dismiss the value of a good lid. It might not seem like much considering we always want the sides of our compost bin open to allow for air circulation, but throwing a lid over it can help to tamp down the worst of the odor emanating from your compost pile.

Follow the tips above, and don’t hesitate to reposition your compost pile before it gets too big to move so you won’t have to deal with nasty smells quite as much.

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