What Is Good for Using As A Compost Activator?

  • By: composthq
  • Date: March 14, 2023
  • Time to read: 5 min.

Has your compost not been breaking down as it should? More than likely, you need to activate the microorganisms within the compost so that decomposition can start taking place. However, you are probably wondering, what is good for using as a compost activator?

Substances with high nitrogen levels are good for using as a compost activator. 

Why Do You Need Compost Activators?

Compost activators, also known as compost accelerators, help to speed up the decomposition process. The microorganisms within your compost require nitrogen to build proteins. Without it, they are unable to reproduce. 

You can choose to add either natural or commercial activators to boost the nitrogen levels within the compost. By doing so, you boost the number of microorganisms decomposing the compost. Thus, increasing the rate of decomposition. 

Natural Compost Activators

You can use organic materials from around your house and garden to activate your compost. As long as they are high in nitrogen, they will get the job done. Here are a few options to consider. 

Coffee Grounds 

Coffee grounds are rich in nitrogen and prevalent in most households. Instead of throwing them out, consider adding them to your pile. 

For cold composting systems, you can add them to the pile each time you have them available to you. 

For hot composting systems, mix the coffee grounds with grass to create a green layer.

Some people even suggest mixing the grounds with lime for the best results. 

Green Plants

Certain green plants you may find in your garden or kitchen that are high in nitrogen may also act as great compost activators. 

Some plants that are nitrogen-rich include:

  • Alfalfa
  • Beans
  • Clover
  • Comfrey 
  • Grass clippings
  • Nettles
  • Peas
  • Seaweed

Adding a few of these plants throughout your pile can significantly boost nitrogen levels.

Human Urine

Surprisingly, human urine is often recommended as a compost accelerant. Urine is nitrogen-rich and mostly comprised of water.

Therefore it can easily travel throughout the compost to make the nitrogen more easily available to the microbes that need it. 

However, since urine is mostly water, it is not as effective in extremely moist compost piles because the urine will not seep into the pile as much as it would in a dry pile.

Also, the microbes are already surrounded by plenty of water and are therefore less likely to take more in during moist conditions.


It is no surprise that manure makes a great compost accelerator since it is what we most commonly think of when we think of natural fertilizers. Manure is very nitrogen-rich, and readily available if you have farm animals. 

You can even purchase dry manure in the form of pellets to sprinkle amongst your compost.

Common animals to use manure from are:

  • Alpacas
  • Chickens
  • Cows
  • Horses
  • Pigs
  • Rabbits

Horse manure may not be the best choice due to possible pesticides and undigested seeds within it. 

Commercially Available Activators

If your looking to purchase a compost accelerator that is sure to get the job done, consider one of these products. 

Jobe’s Organics Compost Starter

This accelerator is composed of a mixture of:

  • Archaea
  • Bacteria
  • Fungi

It comes in a granular form for about $11. 

Sun Mar Compost Magic

This compost accelerator brick helps to keep the compost moist and porous to ensure microbes get enough water and air. Each package includes about 6 bricks for about $26. 

Espoma Organic Traditions Compost Starter

This compost starter is composed of 100% bio-organic material. It contains billions of microbes and heat active varieties to ensure even the most difficult materials break down. You can get this product for about $17. 

Compost-It Compost Accelerator

This accelerator comes with over 60 active ingredients with zero chemicals. It claims to produce nutrient-rich compost in as little as 4 weeks. You can get it for about $12. 

How To Make Your Own Compost Activator

If you want to make your own special blend of compost activator, there are different ways to go about it. You could simply add finished compost to the pile to introduce new microbes, or you can blend together a few different ingredients as the commercial accelerants do. 

Beer and Cola Recipe

This recipe requires:

  • A gallon of warm water
  • One can of flat, warm beer (avoid light beers)
  • One can of cola (make sure it is NOT sugar-free)
  • A half-cup of household ammonia

Pour the water into a 5-gallon bucket and then add in the other ingredients. Fully blend the solution and then pour it over your compost pile.

Mix it into the pile using a shovel or rake. For best results, add a few scoops of garden soil as well. 

Beer contains yeast which encourages the growth of the microbes.

The cola contains sugar which provides needed carbon to the microbes, while the ammonia contains high levels of nitrogen. 

Dry Yeast and Molasses Recipe

This recipe requires:

  • 2 shovel fulls of garden soil
  • One packet of dry yeast
  • ¼ cup of molasses 
  • Warm water

Place the soil, yeast, and molasses within a 5-gallon bucket. Then fill the bucket with warm water until the mixture is about 3 inches from the top.

Fully blend the mixture and then set it in the sun. Continue to mix the mixture every couple of hours for about 48 hours. 

After it has fully been mixed for 48 hours, pour the mixture over your compost pile and consider stirring it in with a shovel or rake. 

The molasses contains a lot of different nutrients, sugar, and carbon which help the microbes thrive. 

Nitrogen Rich Substances Make Good Compost Accelerators

If your compost isn’t breaking down at the rate it should, it’s likely time to introduce an activator to it. Compost performs its best when there is a 30:1 carbon to nitrogen ratio.

Therefore, a nitrogen-rich activator is likely the necessary ingredient your compost needs to thrive when this ratio is off. 

You can use naturally occurring substances from around your house and yard, purchase a commercially made activator, or create your own mixture.

No matter what option you choose, your compost will greatly benefit from it. 

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