Compost Smells Like Poop or Manure? Here’s How to Fix It

Making your own compost is not only satisfying but one of the best ways to add nutrients to your garden. However, nothing is more annoying than dealing with compost that smells like poop. Opening that compost bin and having to deal with the stench daily isn’t pleasant.

Compost has a naturally earthy smell, but if you notice a sulfur-like aroma wafting from your compost bin, that shows that the compost isn’t decomposing correctly. Smelly compost can be due to various issues, which are all addressable and invariably fixable. Read on to learn more about why compost smells like poop and ways to fix it. 

Reasons Why Your Compost Stinks of Poop

There are a few reasons as to why your compost could be stinking. Here’s a closer look at what might be causing an unpleasant stench in your compost heap: 

Green and Brown Material Imbalance

When creating a compost pile it’s important to layer green and brown materials. Having a balance of these two ingredients regulates the high nitrogen (green) and low nitrogen/high carbon (brown) materials you are adding to your compost pile.

Improper layering can lead to stinky compost, lack of heating, and a slower breakdown of your pile. Keeping your compost at a ratio of 30:1 browns to greens and adjusting as necessary can help avoid stinky compost. 

Adding in the following greens and browns can promote a healthy compost pile:

Greens (High Nitrogen)Browns (High Carbon)
Grass ClippingsFall Leaves
Vegetable and Fruit ScrapsTwigs/Branches/Pine Needles
Coffee Grounds/Tea BagsPaper (newspaper, paper plates, napkins)
Animal Manure (no dog or cat)Cardboard (not coated with wax)

It’s important to note that some greens can turn to browns, such as grass clippings, so you should always adjust your compost pile accordingly. 

Wet Compost

Moist compost is standard during spring and fall. A slimy texture and compost that’s turning black could indicate an ongoing exposure to moisture that could be doing more harm than good.

The problem with wet compost is that it lacks aeration, which is needed to decompose the organic material. Instead of composting, the pile starts rotting. 

A lot of moisture in the compost also results in oxygen depletion, contributing to smelly compost. 

Too Compacted

Compaction occurs when you continue adding compostable materials to the top of a pile and then forget to turn it regularly. This causes the pile to break down without mixing the materials and the various components get compacted together as more weight is piled on top. 

Composting requires oxygen. A compost pile that’s too compact means there’s restricted airflow, which interrupts the decomposition process.

All the usable oxygen is used up when materials are piled tightly together, and this prevents any microbial activity from occurring. The lack of oxygen causes the compost to produce hydrogen sulfide, which smells like rotten eggs.

How to Fix Smelly Compost?

Composting requires you to follow some straightforward but specific rules. Here are all the hints, tips, and tricks that I use to help prevent a foul odor in my compost pile, and ways I go about fixing any unwanted whiffs.

Mix the Greens and Browns in Equal Proportions

Avoid having too much nitrogen-rich material in a pile. According to the U.S. Environmental Protection Agency, you should have three parts brown to one part green materials. 

Brown materials can include:

  • Dried weeds 
  • Dried leaves 
  • Dried straw 
  • Sawdust
  • Tiny wood chips

You can also use shredded cardboard and newspaper as brown material. The green matter gets smelly with time, but adding enough brown material helps to curb this smell.

Turn the Compost Pile

Having a compacted compost bin can make it smelly. You need to turn the compost once or twice a week.

Frequently turning the pile adds oxygen, resulting in faster compost production and less smelly compost. Turning the compost will also ensure you have a good mix of greens and browns, and this is essential for any compost. Start by sticking a shovel or pitchfork in the compost pile to mix it up. 

You can also avoid compacting your pile by gently laying down layers of green and brown matter.

Additionally, it may seem a little time-consuming, but having small pieces like shredded/chopped plant matter, leaves, and other food scraps increases the amount of air circulating around the composting microorganisms and this minimizes the risk of smelly compost.

This is a job that kids or grandkids can get involved with. Oh, how my kids used to love getting messy whilst cutting up the veggie peelings, a pile of leaves, and some old egg cartons. It’s a great way to get kids involved with nature and gardening as well as encourage them to recycle household waste and save money.

Keep the Pile Dry

Moisture is essential for decomposing, but having your compost wet for prolonged periods can make it smelly.

If you notice that the compost is becoming slimy, you should add more dry material such as cardboard and dry leaves. That will help to absorb the moisture and keep the pile dry.

Also, find out if the compost pile is in the lowest part of the yard. You could be having your compost in an area where water collects, making it wet for more extended periods. Move the pile or bin to a dry location. 

During the rainy season, the pile may also get wet. Cover the pile when rain is heavy to keep excess moisture off the stack. If you’re using a tumbler or plastic square bins, ensure that the bottom isn’t covered.

Having a covered bottom prevents the compost from draining any excess water. The bin needs to be part of the ground, whether you’re placing it on concrete or a tarp. 

Avoid Adding Certain Things Into Your Compost

Avoid adding items like animal fat, dairy, meat, and oils as these give off a foul smell and attract pests into your composter. These items don’t break down quickly like organic material. Instead of decomposing, they rot away and can leave a stinky smell to your compost. 

Try to Balance the Moisture Content in Your Compost

One of the causes of smelly compost is having a wet compost pile. Whilst moisture is necessary to break down plant matter, too much can cause problems. Look out for patches or areas that have turned black and look slimy. This is an indication (together with an unpleasant smell) that your compost heap needs to dry out a little.

Having compost that is too dry can also be a problem. Dry compost slows down the decomposition process, and this can also make it smelly.

If you notice that your compost is too dry, add some moisture by spraying it with a garden hose. Doing this will increase the heat generated and boost bacterial activity to help with decomposition.

Can You Use Smelly Compost?

We all know that a compost heap doesn’t exactly smell like a bed of roses and will always omit an earthy aroma but you should definitely avoid using pungent or foul-smelling compost. 

An excessively smelly compost pile means that the decomposition process hasn’t occurred as it should. You don’t want to use smelly compost as mulch around a seedbed or valuable plants that are intended for human consumption. Also, the compost won’t have the nutrients required to support plant growth. 

What Should Compost Smell Like?

A well-balanced and maintained compost has an earthy and light scent. When completely broken down, compost smells like rich, fresh garden soil. It doesn’t smell like rotten eggs or manure. Another option is to try a worm composter. This is clean, smells less, and won’t attract flies, as well as a fun way to get your compost directly from kitchen waste and scraps.

Final Thoughts: Compost Smells Like Poop

Compost should have a neutral earthy smell and not produce a strong odor. Any compost that smells like poop or manure is an indication that something is a miss. Too much moisture, lack of green matter, and not enough aeration can cause your compost to smell.

Fortunately, just by making a few simple corrections and sticking with a few basics, you can reduce the foul odor and have a healthy and free bunch of compost to use in your garden.

If you want to take your composting to the next level, why not learn how to make my 6-step easy compost tea recipe? It’s a great way to make your compost go even further by creating your very own liquid fertilizer.