Keep your compost pile cooking all winter long
Compost is often referred to as “gardener’s gold” and rightfully so. Its ability to add organic matter, nutrients, and beneficial microbes to the soil, along with improving the soil’s over all structure, is unparalleled. Adding compost to our clay-based soils opens up pores within the soil to allow easier passage for air, water and dissolved nutrients. It improves plant growth and feeds beneficial microbes that, in turn, make nutrients available to plants for fueling growth.
Compost is also a known disease suppressor, with university research pointing out that plants grown in soils regularly amended with compost have a marked reduction in disease, particularly those diseases caused by soil borne pathogens. In a nutshell, compost promotes biologically active and diverse soil. Plus, it keeps a lot of yard waste out of the landfills.
If you’ve ever purchased compost by the bag or the truckload, you know it can be costly, especially if you need a lot of it. Ideally, you should add a few inches of compost to all your planting beds each season, especially the vegetable garden and annual flower beds. Tree and shrub plantings are deeper rooted, so slower-decomposing shredded bark mulch is a better choice for these areas. But compost’s rapid decomposition and nutrient release is ideal for amending soil in beds where annual plantings are grown.
Instead of purchasing compost, many gardeners find it beneficial to make their own compost from yard trimmings, kitchen scraps, fall leaves, grass clippings and other materials. While you can pile up these ingredients in a corner of the yard or a compost bin and eventually you’ll get compost, it pays big dividends to pay attention to your compost as it “cooks.” Adding ingredients in the proper ratio and mixing them a few times a month results in faster compost production and a good ratio of carbon to nitrogen in the finished product.
The first step in getting your pile to properly “cook” is to pick the right ingredients.
There are two basic classes of ingredients constituting a well-balanced compost blend: the carbon suppliers and the nitrogen suppliers.
• Carbon suppliers are materials added to the compost pile in a non-living state. They are usually brown in color and have low moisture content. Carbon suppliers are slow to decompose, so they take longer to fully break down. All those leaves you have fit into this category, as does shredded cardboard, newspaper, straw, hay and sawdust.
• Nitrogen suppliers are those ingredients used in a fresh state. Nitrogen suppliers are often green in color (except in the case of manures) and have high moisture content. Because they contain many sugars and starches, they are quick to decompose. Nitrogen suppliers include your grass clippings, plant trimmings, manures, spent garden plants and kitchen scraps.
The proportion of these two ingredients (known as the carbon to nitrogen ratio) is an important factor in determining how well the pile breaks down. If you have too much of one ingredient and not enough of another, the pile doesn’t “cook” as well.
The pile should contain about two to three times more carbon materials than nitrogen materials (by volume). So for every 5 gallon bucket of fresh green grass clippings, three 5 gallon buckets of straw or leaves will also have to be added.
Fall is a great time to build a new compost pile or add to an existing one, since autumn leaves are plentiful. Just be sure to balance your leaves with some manure or another green, nitrogen-supplying ingredient to make great compost fast.
To keep the pile actively composting through the winter, continue to turn the compost once or twice a month. Introducing air into the center of the pile is important since the microbes digesting the compost ingredients need air to survive (aerobic). If no air is introduced into the pile, a different set of microbes are at work and the pile can become smelly and take a long time to decompose (anaerobic).
You can turn your pile with an official compost turning tool, a pitch fork, a shovel or even a small rototiller.
Horticulturist Jessica Walliser co-hosts “The Organic Gardeners” at 7 a.m. Sundays on KDKA Radio with Doug Oster. She is the author of several gardening books, including “Attracting Beneficial Bugs to Your Garden,” “Good Bug, Bad Bug,” and her newest title, “Container Gardening Complete.” Her website is jessicawalliser.com. Send your gardening or landscaping questions to [email protected] or The Good Earth, 622 Cabin Hill Drive, Greensburg, PA 15601.