How to Make Microbes Activate in Compost


The key to having a successful compost pile is encouraging lots of microbial activity. In order to decompose organic waste quickly, bacteria need the right balance of carbon, nitrogen, air and water. Using a compost activator jump-starts compost microbial action by increasing the number of microbes in your pile. It also provides them with a ready supply of nitrogen so they can grow and reproduce more quickly. Although you can use commercial compost activators, the University of Illinois Cooperative Extension suggests that you stick with organic activators, such as plain topsoil or finished compost, because they contain protein.

Step 1

Collect your compost materials. Find a mix of nitrogen-rich ingredients (such as fresh lawn clippings, fruit scraps, vegetable peels and coffee grounds) and carbon-rich ingredients (such as straw, dead leaves, old hay, newspaper and cardboard). Try to gather equal amounts of high-carbon materials and high-nitrogen materials so the millions of decomposing bacteria have a ready source of both energy and protein.

Step 2

Spread a 4-to-6-inch layer of high-carbon organic materials across the bare earth to give the decomposing bacteria in the soil immediate access to your organic waste. Top this with a 2-to-3-inch layer of high-nitrogen organic materials. Spray the layers with a light misting of water with your garden hose; your goal is to keep the compost materials about as damp as a wrung-out sponge.

Step 3

Sprinkle 5 to 10 handfuls of finished compost or plain topsoil on top of your double layer of organic waste to introduce additional microbes to your compost heap. Top this with another set of moist carbon and nitrogen layers, followed by 5 to 10 handfuls of finished compost or plain topsoil. Repeat this process until your compost pile is minimally 3 feet tall.

Step 4

Wait at least 48 hours to allow the microbes to begin their decomposing activity. Stir up your compost pile with a manure fork to introduce fresh oxygen to the organic waste.

Things You'll Need

  • Nitrogen-rich organic waste
  • Carbon-rich organic waste
  • Finished compost or plain topsoil
  • Manure fork


  • The University of Illinois Cooperative Extension: Materials for Composting
  • The University of Illinois Cooperative Extension: The Science of Composting
Keywords: compost activator, compost bacteria, fast compost

About this Author

Regan Hennessy has been writing professionally for 11 years. A freelance copywriter and certified teacher, Hennessy specializes in the areas of parenting, health, education, agriculture and personal finance. During her time with Demand Studios, Hennessy has produced content for Ehow, Answerbag and Travels. Hennessy graduated from Lycoming College with a Bachelor of Arts degree in English.