How to Fix Bad Smelling Compost

If you're compost smells, then you're doing something wrong. How can you fix the problem?

When I first started composting, I made many mistakes. One of them was that my compost smelled horrible.

How did I fix this?

Compost Should Not Smell Bad

A well-balanced compost pile should not smell bad. There is something wrong if the decomposing material doesn’t smell like dirt. Most likely, the pile isn’t heating up enough to break down the organic material.

Manure Is the One Exception

If you have added manure to your pile, you will have to deal with foul odors. Until the manure breaks down, it will smell bad. 

If you want to contain the bad smell, you can cover the pile with straw, leaves, or even newspaper. 

What Should It Smell Like?

If you have a healthy pile, then you shouldn’t smell much of anything. Its odor should be faint, like how grass smells after a rainstorm. 

A bin full of food waste for disposal

Why Does It Smell?

If you detect a bad odor coming from the decomposing materials, there might be several different reasons:

  • You’ve added too much green material.
  • Your pile is not stacked correctly.
  • Your pile is not receiving enough air.
  • Your pile has too much moisture.
  • You’ve added oil, fat, meat, or milk to your pile.

Below we will examine each of these reasons and give you a solution to the problem!

5 Ways to Fix Foul Odors

1. You’ve Added Too Much Green Material

If your pile has an eggy or ammonia-like smell, it means that you don’t have enough brown material in the compost.

There should be a ratio of 2:1 of brown-to-green material to make good compost that doesn’t smell.

If you made the mistake of using too much green material, then the easiest way to fix it is to add a thick layer of brown material every time you add a layer of green material.

A person shoveling fertilizers from the backyard compost

2. Your Pile Is Not Receiving Enough Air

Oxygen is the most important player during decomposition. A lack of oxygen will cause the bin or pile to smell like rotten eggs because of anaerobic decomposition. Yuck!

To fix this, you can stir or turn your compost on a regular basis. Mix things up with a pitchfork or shovel. Make sure your compost pile doesn’t get compressed.

Another way to allow proper aeration is to lay down alternating layers of green and brown matter. In a densely packed pile or bin, there isn’t enough room for oxygen to get in and break down organic matter.

3. Your Pile Is Not Stacked Correctly

You already know the best ratio of green to brown matter. When you add the different materials to the pile or bin, don’t mix them all together. Instead, layer one on top of each other.

When you build the layers, make sure there is a brown layer on top. Brown matter doesn’t smell bad as it breaks down, unlike green matter, which does smell a little.

4. Your Pile Has Too Much Moisture

Double-check that your storage space is in the right place. It can be tempting to put a compost tumbler or bin right next to the house. But it’s not always the best place. If the runoff from your roof makes its way into the pin, you can end up with a compost tea rain barrel.

If you detect a bad odor, move the tumbler or bin to a sunny spot that is sheltered from extra rain runoff. Once the materials dry off, the bad smell is likely to disappear, especially if you add some brown material to soak up any extra moisture. Turning it to allow for the air to flow can also help the pile to dry out.

5. You’ve Added Oil, Fat, Meat or Milk to Your Pile

Some things, like oil, fat, meat, and milk, get stinky once they decompose. Don’t add these things because they will make your pile smell foul. They will also attract animals and maggots.

Keep oil, fat, meat, and dairy out of your compost bins, and you won’t have this issue anymore.

Jeffrey Douglas
Jeffrey Douglas own a landscaping company and has been in the business for over 20 years. He loves all things related to lawns or gardens and believes that proper maintenance is the key to preventing problems in the first place.
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