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How Long Does it Take Compost to Mature?

Compost boosts plant growth and health by adding rich nutrients to the soil, but despite its benefits, you may worry about how long this process takes. Organic materials can take anywhere from three weeks to six months to yield mature compost, but you can speed the process along.
  1. Location

    • Where you have your compost can affect how long it takes the compost to mature. Begin your pile in a flat spot where water drains easily, that gets approximately half a day of indirect sunlight and is protected from strong winds. Standing water, too much sun and wind can all increase the time it takes compost to mature. Avoid starting your pile near trees, as they can sap compost of water and nutrients.

    Pile Size

    • The fastest-maturing compost piles have an area of 3 to 5 cubic feet. Smaller piles will mature more slowly and larger piles can be difficult to turn. This size of pile allows compost to sufficiently heat up, even at its center, encouraging the growth of helpful microorganisms.

    Materials

    • The fastest compost maturation happens when the ratio of carbon to nitrogen is equal. It may be helpful to consider this in terms of a "green" to "brown" ratio. Green materials include grass clippings and vegetable scraps, while brown compost materials include dried leaves, manure and wood chips. Too much green or brown material can slow down the process. If your pile is low on brown materials, add soil or mature compost to improve it. If you lack green materials, add a handful of 10-10-10 fertilizer to add nitrogen. For all materials, increase their surface area by chipping or shredding. This will help bacteria work more efficiently and result in mature compost sooner.

    Moisture

    • Compost should be as moist as a wrung-out sponge. Dry compost matures more slowly than wetter compost, so it is important to check the moisture level and add water as necessary, especially after adding brown material to the pile. If your pile gets too wet, add brown material to absorb excess water.

    Turning Frequency

    • For bacteria to break down plant material, they must receive oxygen. For the fastest maturity, turn your compost pile frequently, every two to four weeks, pulling the materials at the pile's edges toward the center. Do not turn more often than every two weeks, as the materials at the center will not have time to decompose. In winter, bacteria are less active so avoid turning compost after November to prevent heat from escaping. If you turn the pile frequently, compost can mature in as little as three months.