Experienced organic gardeners know that the best carbon to nitrogen ratio for a successful compost pile is 30:1. This seems like a large amount of carbon-rich materials compared to nitrogen-rich materials, but gardeners with an abundance of fall leaves, straw, sawdust, or cornstalks may face a wait of several years before they harvest dark humus for the garden. Using compost activators, also known as compost starters or compost accelerants, can turn a cold compost pile into one that’s steaming and active.
Why Gardeners Need Compost Activators
Anyone who has set foot in a forest has observed the composting process, even if he hasn’t maintained a compost bin for the garden. Leaves fall to the forest floor, where they eventually decay into humus that nourishes the next generation of trees and plants. We can observe the mix of carbon and nitrogen ingredients that we attempt to duplicate in our own compost piles, but there’s an invisible composting agent that causes the composting process: microorganisms.
During the composting process, microorganisms turn carbon into energy, which causes the steam one observes rising from an active compost pile. However, these microorganisms need nutrition from nitrogen to break down the carbon containing materials. Without ample nitrogen, the compost pile will remain cold and inactive. With the addition of a compost starter, a pile can generate temperatures in excess of 150 degrees F.
Compost Accelerators for Quick Composting
Commercial compost accelerators and compost starters are made of organic materials high in nitrogen. Common activators may include ingredients such as fishmeal, blood meal, bone meal, alfalfa meal, or horn meal. In addition to these nitrogenous ingredients, many compost starters are inoculated with the beneficial microorganisms that can break down carbon-rich materials.
Some compost activator products claim that their microorganisms are special strains of bacteria that work efficiently at high temperatures, hastening the composting process. Horticulturalists debate the efficacy of bacterial or fungal cultures as a standalone compost starter, so gardeners should purchase compost activators that provide a mix of nitrogenous ingredients in addition to beneficial microbes.
Homemade Compost Starter
In a pinch, gardeners can add a few shovelfuls of garden soil, or better yet, finished compost to the compost bin that’s too high in carbon-rich materials. Although many materials contain higher amounts of nitrogen than finished compost or soil, these natural compost activators are readily available, and they contain beneficial microorganisms that kick start the composting process.
Source:
Rodale, R. (1999). The Encyclopedia of Organic Gardening. Rodale Books, Inc: Emmaus, PA.
Jamie McIntosh - Jamie has written hundreds of garden articles for the web, and is your guide to Flowers on About.com.
