Here’s the Dirt on Compost
Compost is the biologically active material (humus) that results from the decomposition of organic matter under controlled conditions. Organic matter such as grass clippings (untreated with herbicides), leaves, twigs, old vegetable plants or annuals, vegetable peelings and coffee grounds can be composted. The end result is a finely textured, nutrient-rich organic matter called humus, also known as soil conditioner, soil amendment or, simply, compost.
Another type of compost is vermicompost (aka vermiculture or worm composting). Vermiculture uses worms to eat nutrient-rich fruit and vegetable scraps that turn into nutrient-rich compost. This kid-friendly project easily can be set up indoors. Cornell University offers worm composting basics at http://compost.css.cornell.edu/worms/wormhome.html.
When buying bulk compost or soil mix, ask the vendor how they control herbicide contamination risk. Unfortunately, some bulk compost contains products that were previously treated with an herbicide. This can transfer to your garden, causing damage to plants or lawns. Check the compost pile for any weed growth to prevent importing weed seeds into your garden. Compost should be weed free, resemble dark topsoil, have a light, and crumbly texture with no visible remains of the original plant material.
The Benefits of Using Compost
Compost improves the soil’s ability to retain moisture, whether in potted plants, vegetable gardens, landscape beds or lawns. It aerates the soil, increases the activity of soil organisms, makes nutrients more available to plants, improves the overall structure and texture of native soil. Compost improves the drainage and aeration of the heavy clay soil in our region, and reduces waterlog damage to plants.
Use compost to amend garden soil prior to planting. Give it enough time to incorporate with the existing soil, which takes anywhere from a few weeks to a couple of months. Then soil test and fertilize accordingly, depending on what you are planting. Make note that compost is a soil conditioner or amendment, not a fertilizer, so the addition of some supplemental fertilizer may be necessary.
You can spread compost on top of potting soils, as a mulch or top dressing in planted areas. Compost can be used in preparation for new lawns or to top-dress existing lawns.
Multiple online resources can explain how to create a compost pile. Visit https://extension.uga.edu/publications and search for Composting and Mulching, Circular 816, or Composting: Recycling Landscape Trimmings, Circular 981.
• U.S. Composting Council, https://www.compostingcouncil.org/page/CompostBenefits
• U.S. Environmental Protection Agency, https://www.epa.gov/recycle/composting-home
• Compost Foundation, https://www.compostfoundation.org/Education/Composting-Resources
• JoeGardener YouTube video How To Add Compost In The Garden, https://www.youtube.com/watch?v=EzSauADY4UU.
The Master Gardener Volunteers of Cobb County (MGVOCC) supports the University of Georgia Cooperative Extension Service and strives to improve the quality of life in our community by delivering research-based horticultural information, educational programs and projects.
– Master Gardener Volunteers of Cobb County is a part of the University of Georgia Extension in Marietta.